Based on the Marvel Previews #65, January for March 2009, I'd say you need to pre-order the following books in order to keep up with Spider-Man.
Core Titles
Amazing Spider-Girl #30
Amazing Spider-Man #588
Amazing Spider-Man #588, king variant cover
Amazing Spider-Man #589
Amazing Spider-Man Extra! #3
Marvel Adventures Avengers #34
Marvel Adventures Spider-Man #49
New Avengers #51
Spider-Man & The Human Torch In... Bahia De Los Muertos
Spider-Man Y La Antocha Humana En... Bahia De Los Muertos Edicion Boricua En
Espanol
Spider-Man: Noir #4, Patrick Zircher cover
Spider-Man: Noir #4, Dennis Calero variant cover
Ultimate Spider-Man #132
Guest Apps
Avengers / Invaders #9
Avengers / Invaders #9, Alex Ross sketch variant cover
Avengers / Invaders #9, Arthur Suydam variant cover
Official Index To The Marvel Universe #3
Ultimatum #4
Ultimatum #4, variant cover by Ed McGuiness
Ultimatum #4, variant sketch cover by Ed McGuiness
Reprints
Avengers: Hawkeye Premiere HC
Avengers: Hawkeye Premiere HC, variant edition
Marvel Adventures Two-In-One #21
Marvel Masterworks: Warlock Vol. 2
Marvel Masterworks: Warlock Vol. 2, variant edition
Secret Invasion: The Amazing Spider-Man TPB
Spider-Man loves Mary Jane: Sophomore Jinx Premiere HC
Spider-Man loves Mary Jane: Sophomore Jinx Premiere HC, direct market
variant
Spider-Man: Brand New Day #6
Ultimate Spider-Man: Power & Responsibility Premiere HC