Hi. Over the years my interest in Marvel Comics has grown, probably because of the movies, and I figures now is as good a time as any to get into the medium. I picked up a couple books from my local comic book store, However after reading them I was very confused on what was going on. So is there a definitive place to start reading Marvel Comics? Any recommendations?

Some characters I am interested in are:
Captain America
Iron Man
Thor
Daredevil
Spider-Man