From http://www.adaptivepath.com/ideas/designing-search-checklist
Recently on projects I’ve found myself designing a number of search results pages. While each project has its own set of requirements and nuances, I think there are a handful of elements that should be included in most all result page interfaces. If you start out with this list, and then tweak as your situation requires, I think you’ll end up with a pretty good page.
Here are the items on my checklist, in no particular order:
* Directory crowding - don’t let one source of hits crowd out the results, show a sample and link to more.
* Spellchecking - no longer a luxury, it allows users to get close enough to a search result, especialy proper nouns.
* Keymatch results - for those times when you can infer from the query what users are most likely looking for.
Interestingly, if you add the Page Rank algorithm to your list, you’ve got Google.
Give the user great feedback when no results are found.
Make sure you are using different colors for visited and unvisited links.
When search results are documents (pdf’s etc) give introductory text (e.g., the abstract) to the document.