My little guys loved books by Eric Carle and Sandra Boynton the best when they were tiny. “Goodnight, Moon” was a favorite, too, of course, as was “Pat the Bunny.” They are also starting to get into Dr. Seuss (they are 2 and 3 1/2) and especially like “Green Eggs and Ham.”
As for music, we do lots and lots of classical, especially Vivaldi and Bach, mostly because they’re among my favorites, and tend to be cheerful. (I also love Mussorgsky, but some of it is pretty dark and scary for kids!) I do listen to lots of other stuff, too, though — some pop, classic alternative, classic rock, oldies, country, punk, etc. (I have to admit, it warmed the cockles of my once punk-rock heart to see my 2yo dancing to the Descendents!)