Get 'Willie Dixons Blues Dixonary' its a 5 album box set of the great mans work. Everything you want is in there, treat it as your 'learning bible'. Next the complete box set of the Chess Recordings, its a 12 album Box set and features many classic recording. The complete works of Stax singles is another great box set, now a 3 Album box set.

Also the Alligator Records 40th anniversary box set is another great album. If you are into the Blues, do a search for 'Blues Record Labels' and you will find many fantastic artists old and new. One of my favourites of the new breed of young artists is Kilborn Alley Blues Band, who hail from Chicago and keep the Blues tradition current. Maybe it's more of r&b than blues, but one of my favorite albums is the 'Blues Brothers' movie soundtrack. Duck Dunn's playing is among the all-time greats, so you should also check out his work with Booker T & The MGs.

However, the Blues Bros soundtrack is a must. Since you mentioned Zeppelin, I'll throw out the obligatory 'Lemon Song' recommendation. The bass line is a pretty imaginative representation of the 12-bar blues format, but JPJ's solo is deservedly legendary. A great line to learn effective use of open strings, btw.

There are many generic Blues lines, but what you need to find is the originals, so find a chess catalogue, a Willie Dixon, Catalogue etc and find when the lines were first used. Madhubala tamil serial episode 120. For example 'Bo Diddley' is a classic bass line, as is 'Help me', as is 'Baby i want to be loved' etc. Like i said you need to define what yo call Blues.