If you've not done so recently, definitely check out Webmaster Central . Google is regularly adding new features, and there's an active blog and forum. (High praise for the additional transparency that Google is providing webmasters via this portal.)
SEO tip from Maile:
For human and spider friendliness, keep the number of links on any given webpage to 100 or less. That's both internal and external links.
Hadn't heard that one before.