Personally, I've found the "for dummies" series to be valuable sources.
Jodie foster sent her close friend, Russell Crowe, a copy of Sailing for Dummies while he was preparing for his role in "Master and Commander." He said it was often more useful than the technical books he was studying.
Some years ago I bought a Volkswagen Rabbit, only to have it struck by lightening about 6 months later. There was always something else going wrong with it.
A friend gave me An Idiot's Guide to the Volkswagen Rabbit for Christmas, along with a portable oil can spout and a can of carrot juice. ( same basic concept)
My mechanic got so tired of me bringing it in to show him something he hadn't been able to figure out, he bought a copy for himself.