These are SEO guidelines, not rules. Project specific considerations may be more important than SEO. These are also basic rules. If you're already doing all of these, it's time for a more thorough review of your SEO practices to figure out what to do next.
- Do add brief descriptions to the alt attribute of image tags. The attribute should describe the image, not be a summary of the article.
- Do use H1, h3, and H3 for titles and headings.
- Do create a relevant HTML title for every page. Using the actual article title that appears in the page is a good idea.
- Do use style sheets as much as possible to keep the page size low.
- Do use brief and relevant meta tags (keywords and descriptions) to provide a backup for the description that appears in search engine listings.
- Don't fill the meta tags with words that don't appear in the content of the page. The exception to this is to put common misspellings in the meta tags.
- Don't repeat meta tag content on every page. The content should be specific to the page.
- Do create separate sites rather than making a site a sub-site of a larger one.
- Do not make every visit to a URL unique by appending a session ID or something similar.
- Do create a site map. This is as much for users as for search engines as it can serve as a gateway to deep content.
- Don't link to redirects. Better to link directly to the destination page.
Images, Flash, Video
- Don't create images that contain only text i.e. if an image contains just text, consider using HTML instead.
- Don't put content in Flash movies. Better to have the content outside of the Flash and in the HTML.
- Do provide a transcript for video or audio interviews.
Copy and Content
- Do create a title that uses words that describe the main theme of the article.
- Do use headings and sub-headings that describe the main theme of the copy that follows.
- Don't automatically swap out repeated words and phrases in favor of less common words and phrases.
- Do post all content on the website including newsletters.
- Do keep all special content such as Christmas, Halloween, Thanksgiving specials on-line.
- Don't use pop-up windows for content. If pop-ups are necessary, provide an alternative link to the same page that isn't a pop-up.
- Don't remove content from a website.
- Do make sure all content, in particular old content, has a link pointing to it. Use a site map or archive list page if necessary.
- Do allow search engines to view forum discussions. This is free content.
- Do update content as often as possible. Search engines like frequently updated sites and will visit more frequently.
- Don't worry about writing articles that are too long. The longer the better when it comes to SEO.
- Do use link text that is relevant to the destination page.
- Don't create links that read “click here” or “read more”.
- Don't create links out of entire sentences.
- Don't fill the page footer with links to other sites. Better to keep the list short.
- Do cross-link between pages in the website.
- Do link to external sites.
- Do encourage external sites to link to specific content. Many sites are open to sharing links.
- Need help deciding which words or phrases are more commonly searched for? Try this site: Google Keyword Tool. The higher the number for a word, the more common the search.
- Need help deciding which words or phrases are most common on existing websites? Try a search at http://www.google.com and the total result count at the top of the page.
- To perform a more thorough analysis of search behavior, try http://www.wordtracker.com (there is a fee).
- To see what other site owners are talking about, visit http://www.webmasterworld.com (some discussions are free to read, others require a donation).