Google Do
- Keep the links on a given page to a reasonable number. Lower then 100. Pages with more links are not automatically considered spammy by Google, but it is not recommended to go beyond 100.
- Offer a site map to your users with links that point to the important parts of your site. If the site map has an extremely large number of links, you may want to break the site map into multiple pages.
- Make sure that your <title> elements and ALT attributes are descriptive and accurate.
- Check for broken links.
- Make reasonable efforts to ensure that advertisements do not affect search engine rankings. Use rel=no-follow when appropriate.
Google Don't
- Don't participate in link schemes designed to increase your site's ranking or PageRank. They may be easier to detect then you think.
- Don't link to web spammers or "bad neighborhoods" , as ranking may be affected adversely by those links.
- Do not use hidden links.
- Do not make all links 'no-follow'. If a link is nofollowed, that PageRank doesn't go out on the other links instead.