I just printed off a set of maps from maps.google.com to help navigate while driving from SFO to Sonoma State University (via downtown San Francisco to pick up Tim at SFMOMA). Incredibly detailed and easy to read maps, with great easy-to-follow descriptions.
I ended up printing off about 6 different maps, for different portions of the trip (zoomed appropriately). Much better than having to lug around a big "Bay Area Streetmap" atlas.
For example - this view of the 101/280 interchanges south of downtown, with the offramp that will get us to SFMOMA (or this cool alternate view using satellite imagery to help get landmarks straight).