Importance:
Medium
GG advises on techniques to ensure indexing.
GoogleGuy Says: [
Link to quote]
Site maps.. GOOOD. Weird linking methods.. BAAAAD
I recommend a tree-like structure where you can always get from the higher levels down to the more specific levels. Other structures work too, o' course, but when in doubt I'd go with a site map and a simple linking structure so that you can reach every page via the root page, or a page that the root page can reach.