Based on the Marvel Previews #7, February for April 2013, I'd say you need to pre-order the following books in order to keep up with Spider-Man.
Core Titles
Avenging Spider-Man #19
Marvel Universe Ultimate Spider-Man #13
Scarlet Spider #16
Superior Spider-Man #7
Superior Spider-Man #8
Ultimate Spider-Man #22
Guest Apps
Age Of Ultron #5
Age Of Ultron #5, Adi Granov variant
Age Of Ultron #5, Rock-He Kim variant
Spin-Offs
Alpha: Big Time #3
Venom #33
Venom #34
Reprints
Avenging Spider-Man: Threats & Menaces TPB
Marvel Universe Ultimate Spider-Man Vol. 3 Digest TPB
Spider-Man: Danger Zone TPB
Spider-Men TPB
Ultimate Comics Spider-Man By Brian Michael Bendis Vol. 3 TPB