Here's an article about the importance of search engines that raises a few old points but a few very interesting ones (even though I'm skeptical, they're worth mentioning).
1. Don't expect users to spend much time navigating through your site. Provide relevant links to your context on the probable lnading pages.
2. Some search engines will penalize you for using keywords in the stem of a URL. This means that www.seo-search-engine-ranking.com would be OK but www.whatever.com/seo.html would not be. This of course is pretty worthless without some mention about which search engines. If we're talking about Google, this is important. If we're talking about Ted's search engine, no one cares.
3. "Relevancy is vital. Some search engines will also penalize a site for irrelevant links or irrelevant keywords." Again, which search engines?
4. Pointer pages should have useful content according to this article. Really thoguh, I suppose any relevant content would do. The search engine spider will never know if the content is actually useful to humans. They used to do this based on link popularity, but I bet a pointer site with crappy content could find lots of reciprocal link partners these days...
Trade links with seo-search-engine-ranking.com
http://www.seo-search-engine-ranking.com/ad_network_222.php