Search engine optimization is on every webmaster's mind these days. Achieving a favorable ranking for the right keywords can mean a steady stream of targeted traffic to your site, and all for free - that's hard to beat. The key to high search engine rankings is structuring your website correctly, including plenty of content that is relevant to your keywords, and making sure your website is spider-friendly. You can use this checklist to make sure all of your Web pages can be found, indexed and ranked correctly:

Your website is themed. ?Your site deals with an identifiable theme which is obvious from the text on the home page and reinforced by all the other pages on your site. In other words, all the individual Web pages relate to each other and deal with various aspects of some central theme. The text on your home page should state clearly what that theme is and what your website is about, and the other pages should reinforce that.

Your Web pages have enough high quality, relevant content. ?Spiders come to your website looking for content. If a page doesn't have much content, or the content doesn't appear closely related to the page's title and your website's theme, the page probably won't be indexed or if it is indexed it won't rank well. Search engines love quality content and lots of it - content is what Web searchers are looking for and search engines try to provide.

Your website's navigational structure is relatively flat. ?You don't want important pages to be too "deep" within your website, meaning it takes several clicks to get there from the home page. Search engines typically index the home page first, then gradually index other pages on a site over time. Many spiders are programmed to only go three layers deep - if some of your important content is buried deeper than that, it may never be found and indexed at all.

You've created a unique "Title" tag for each page. ?The title is one of the most important aspects of any Web page from an SEO standpoint, especially for Google (which is the most important search engine to optimize for). Don't use a generic title for all your pages, use the keywords your targeting for that page and keep it brief but descriptive.

You use the "Description" meta tag. ?Contains a highly descriptive sentence about the content and purpose of your page, and contains your most important keyword phrase early in the sentence. Not all of the search engines will display this "canned" description when they list the page in search results, but many of them will, so it's worth getting it right.

You use the "Keywords" meta tag. ?As with the meta tag description, not every search engine will use the keywords meta tag. But some will use it and none will penalize you for having it. Also, having a short list of the keywords you're targeting will help you write appropriate content for each page. The keyword tage should contain your targeted keyword phrase and common variations, common misspellings and related terms. Make sure your keywords relate closely to the page content and tie into the overall theme of your site.

Your keywords are included in the visible page content, preferably high up on the page. ?You have to achieve a balance here - you want to include keyword phrases (and variations) a number of times within your text, but not so many times that you appear to be guilty of "keyword stuffing". The trick is to work the keywords into the text so that it reads as naturally as possible for your site visitors. Remember, you can incorporate keywords into any Web page element that is potentially viewable by site visitors - header text, link text and titles, table captions, the "Alt" attribute of the image tag, the "title" attribute of the link tag, etc.

Every page of your website can be reached by search engine spiders. ?This is critical - if your pages can't be found, they can't be indexed and included in search results, let alone rank well. Search engines use spiders to explore your website and index the pages, so every page must be accessible by following text links. If pages require a password to view, are generated by a script in response to a query, or have a long and complicated URL, spiders may not be able to read them. You need to have simple text links to the pages you want indexed.

You've included a site map. ?Unless your site is very small, it's a good idea to create a site map with text links that you link to the site map from your home page. In addition to a link, include descriptive text for containing the relevant keywords for each page.

You link to your most important pages from other pages on your site. ?Internal links help determine page rank since they show which pages of your site are most important. The more links you have to have to a page, relative to other pages on your site, the more importance search engines will assign to it.

You use keywords in your link text. ?When you create a text link to another page on your site, use that page's targeted keywords as the text for the link (inside the anchor tags that create the link). Make it as descriptive as possible. For example, a link that says "Premium Customized Widgets" is much better than one that says simply "Product Page", and indicates to search engine spiders what that linked page is about.

Your site doesn't use frames. ?If possible, don't use frames on any page you want to get indexed by search engines. If you feel you simply must use frames for a page, then also make use of the "noframes" HTML tags to provide alternative text that spiders can read (and make that text descriptive rather than just a notice that "This site uses frames etc. etc.").

You don't use automatic page redirects. ?Don't make any pages automatically redirect the visitor to another page (the exception is a page you've deleted for good - in which case you should use a "301 redirect", a permanent redirect which is acceptable to search engines).

Your important content is in plain text and not contained in images. ?Search engine spiders can't "read" content in JPEG, GIF, or PNG files. If you really feel that using an image rather than text is crucial to your design, at least put the same text in the image's "Alt" tag (or in the "title" tag if you're using the image as a hyperlink).

Your important content is not contained in Flash files. ?Flash is a wonderful technology, but unfortunately spiders don't have the required "plugin" to view Flash files. As a result, Flash content is mostly inaccessible to search engine spiders. Some can find and follow hyperlinks within the Flash file, but unless those links lead to pages with readable HTML content this won't help you much. Don't create all-Flash pages for any content you want to get indexed - instead, put that content in the HTML portion of the page.

Links and keywords are not hidden inside JavaScript code. ?If your links use JavaScript to direct the user to the appropriate page (for instance, a drop-down list) or important content is contained within JavaScript code (when it's displayed dynamically using DHTML, for instance) search engine spiders won't be able to "see" it. You can, however, use the "noscript" HTML tags to provide an alternative that can be read by spiders.

You've optimized every important page of your website individually. ?Don't stop at your home page. Take the trouble to optimize any page which has a reasonable chance of being indexed by the major search engines, targeting appropriate keywords for each. If you face a lot of competition it may be nearly impossible to get a top ranking for your home page, but you can still get a lot of search engine traffic to your site from other pages which are focused on very specific keyword phrases.

You didn't duplicate content. ?Each page of your site should have unique content that distinguishes it from every other page on your site. Duplicating content or having pages that are only slightly different might be seen as "search engine spamming" (trying to manipulate search engine results).

You provide linking instructions for those who want to link to your site. ?Somewhere on your site state your policies about other people linking to your site and provide the wording you'd like them to use in their link. You want to encourage other people to link to your site, preferably using link text and a description that reflect the keywords for that page. For their convenience provide the ready-made HTML code for the link - not everyone will use it, but most often they will use your preferred text as a courtesy as long as it is truly descriptive of your site and doesn't contain "marketing hype".

You provide linking instructions for those who want to link to your site. ?Somewhere on your site state your policies about other people linking to your site and provide the wording you'd like them to use in their link. You want to encourage other people to link to your site, preferably using link text and a description that reflect the keywords for that page. For their convenience provide the ready-made HTML code for the link - not everyone will use it, but many will use your preferred text as a courtesy as long as it doesn't contain "marketing hype".

Important hyperlinks are plain text links and not image links or image maps. ?Text links are better from an SEO standpoint than image links, as spiders can't read text from an image file. If you feel you really must use a graphic as a link, at least include a text description which (including the relevant keywords) by using the "title" attribute of the link tag.

Your website is free of coding errors and broken links. ?HTML coding errors and non-working links can keep search engine spiders from correctly reading and indexing your pages. For that reason, it's a good idea to use a Web page validation utility to check your HTML code to make sure it's error-free.

Jane McLain is a Web developer and SEO specialist and the webmaster of EClaunchsite.com, an online resource center for netrepreneurs with tools and information to help you plan, build, launch and grow your e-business.