In addition to Google maps, I also use Bing.
With Bing maps you can click on "aerial" view, then click bird's eye view. In this mode, you can get a better view of the street width and see if there is a bike lane or shoulder.
In Google Maps, you can also use the Street view mode (if the view was shot by the Google van). Great way to pan over to see the bike lane, shoulder or parked cars!

This might help you too. I just found the bike lane maps for SD. Here's the link:

http://www.icommutesd.com/Bike/BikeMap.aspx