Most airports are serviced by Super Shuttle. It is a national van shuttle that goes to groupings of hotels. Here's the web link: http://www.supershuttle.com/SFO_shuttle.aspx
and the info from the site:
SJC – Advanced reservations are required. Please call (800) BLUE-VAN (258-3826) to make your reservation. Upon arrival call the same (800) number, select option 1 and provide your reservation number so we can accommodate you. Please wait for your SuperShuttle van by the “Prearranged Pickup” sign located on the curb.
They are very reasonable and according to the site, wheelchair accessible if you let them know in advance.