Based on the Marvel Previews #80, April for June 2010, I'd say you need to pre-order the following books in order to keep up with Spider-Man.
Core Titles
Amazing Spider-Man #546, Marvel's Greatest Comics
Amazing Spider-Man #634, cover by Leinil Francis Yu
Amazing Spider-Man #634, cover by Mike Fyles
Amazing Spider-Man #634, villain variant
Amazing Spider-Man #635, cover by Gabriele Dell'Otto
Amazing Spider-Man #635, cover by Mike Fyles
Amazing Spider-Man #636, cover by TBA
Amazing Spider-Man #636, cover by Mike Fyles
Peter Parker #4
Spectacular Spider-Girl #2
Spider-Ham 25th Anniversary Special #1
Spider-Man, Marvel Adventures #3
Spider-Man: Fever #3
Ultimate Spider-Man #11
Web Of Spider-Man #9
Guest Apps
Amazing Spider-Man Presents: American Son #2
Amazing Spider-Man Presents: Black Cat #1
Amazing Spider-Man Presents: Black Cat #1, variant cover
Avengers #2, regular cover
Avengers #2, special variant cover
Avengers #2, variant cover John Romita Jr.
New Avengers #1, regular cover
New Avengers #1, heroic age blank variant cover
New Avengers #1, variant cover Marko Djurdjevic
New Avengers #1, variant cover Stuart Immonen
Ultimate Avengers 2 #4
Vengeance Of The Moon Knight #9
Reprints
Marvel Masterworks: The Amazing Spider-Man Vol. 12 HC
Marvel Masterworks: The Amazing Spider-Man Vol. 12 HC, variant edition
Peter Porker: The Spectacular Spider-Ham Vol. 1 TPB
Spider-Man & The Secret Wars TPB
Spider-Man: Jackpot TPB
Spider-Man: The Return Of The Black Cat TPB
The List TPB
Thor By Dan Jurgens & John Romita Jr. Vol. 3 TPB
Ultimate Comics Spider-Man: The World According To Peter Parker TPB