Things to do
Below are a few tips for creating a Google-friendly site.
Give visitors the information they're looking for.Provide high-quality content on your pages, especially your homepage. This is the single most important thing to do. If your pages contain useful information, their content will attract many visitors and entice webmasters to link to your site. In creating a helpful, information-rich site, write pages that clearly and accurately describe your topic. Think about the words users would type to find your pages and include those words on your site.
Make sure that other sites link to yours
Links help crawlers find your site and can give your site greater visibility in Google’s search results. When returning results for a search, Google combines PageRank (Google’s view of a page's importance) with sophisticated text-matching techniques to display pages that are both important and relevant to each search. Google counts the number of votes a page receives as part of its Page Rank assessment, interpreting a link from page A to page B as a vote by page A for page B. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important."
Keep in mind that Google’s algorithms can distinguish natural links from unnatural links. Natural links to your site develop as part of the dynamic nature of the web when other sites find your content valuable and think it would be helpful for their visitors. Unnatural links to your site are placed there specifically to make your site look more popular to search engines. Only natural links are useful for the indexing and ranking of your site.
Make your site easily accessible
Build your site with a logical link structure. Every page should be reachable from at least one static text link.
Use a text browser, such as Lynx to examine your site. Most spiders see your site much as Lynx would. If features such as JavaScript, cookies, session IDs, frames, DHTML, or Macromedia Flash keep you from seeing your entire site in a text browser, then spiders may have trouble crawling it.
Consider creating static copies of dynamic pages .Although the Google index includes dynamic pages, they comprise only a small portion of Google index. If you suspect that your dynamically generated pages (such as URLs containing question marks) are causing problems for Google crawler, you might create static copies of these pages. If you create static copies, don't forget to add your dynamic pages to your robots.txt file to prevent Google from treating them as duplicates.
Things to avoid
Don't fill your page with lists of keywords, attempt to "cloak" pages, or put up "crawler only" pages. If your site contains pages, links, or text that you don't intend visitors to see, Google considers those links and pages deceptive and may ignore your site..
Don't use images to display important names, content, or links. Google crawler doesn't recognize text contained in graphics. Use ALT attributes if the main content and keywords on your page can't be formatted in regular HTML.
Don't create multiple copies of a page under different URLs. Many sites offer text-only or printer-friendly versions of pages that contain the same content as the corresponding graphic-rich pages. To ensure that your preferred page is included in Google search results, you'll need to block duplicates from Google’s spiders using a robots.txt file.