Google Webmaster Guidelines... know thy target
Following these guidelines will help Google find, index, and rank your site. Even if you choose not to implement any of these suggestions, we strongly encourage you to pay very close attention to the "Quality Guidelines," which outline some of the illicit practices that may lead to a site being removed entirely from the Google index or otherwise penalized. If a site has been penalized, it may no longer show up in results on Google.com or on any of Google's partner sites.
After reading much of the book ‘search’ (muchly about Google) I have been working out how to get zkimmer pages to blast up the pagerank on Google searches… some very interesting reading amongst these links at the bottom of the Guidelines…
Quality guidelines - specific guidelines
- Avoid hidden text or hidden links.
- Don't use cloaking or sneaky redirects.
- Don't send automated queries to Google.
- Don't load pages with irrelevant keywords.
- Don't create multiple pages, subdomains, or domains with substantially duplicate content.
- Don't create pages that install viruses, trojans, or other badware.
- Avoid "doorway" pages created just for search engines, or other "cookie cutter" approaches such as affiliate programs with little or no original content.
- If your site participates in an affiliate program, make sure that your site adds value. Provide unique and relevant content that gives users a reason to visit your site first.
If you determine that your site doesn't meet these guidelines, you can modify your site so that it does and then submit your site for reconsideration.
All the above I got from a reference to the Google Webmaster Guildelines in the Google Search book.