You're told about the keys as you work through the intro levels, so really you shouldn't need to get a key listing separately. If you need to use a key to do something, the game will usually make that fact very clear, and tell you exactly what to do.

x - jump
xx - high jump

L1 roll
L1 and X for long jump

R1 to fire

D-pad - select weapons

Jetboard
X to jump
X and R1 to flip

Jak and Daxter 3 Walkthrough