>>96477923
PHB1 & 2
DMG 1. Maybe 2.
Rule's Compendium
Monster Manual 3 and Monster Vault.
Adventurer's Vault 1

Past this it's up to your own personal desires to fill in specific things otherwise. Though you got the online database and offline character builder to fill things in too. There's also picrel, which makes running older monster content like MM1 and 2 easier to wing.

Don't listen tot he hate, Anon. 4e is probably one of the more fun editions out there, despite the small list of actual warts. Just understand that it does set piece encounters better than random encounters and you and your table should have a fine time.