Yeah, the pocket and wiring kit is all you need. The stock radio has 2 metal plates on the sides that hold the radio to the car; SAVE THOSE. Unless you're willing to go down to your local Stealership, you're screwed without them.
Basic run-down:
1. Take wiring kit and crimp/twist together the wires with matching color, then cover with electrical tape.
2. Take radio out.
3. retain metal plates and secure onto aftermarket HU (top portion only; bottom makes it harder to put the pocket on).
4. Pull out aftermarket-designed wires near firewall (if you have a JBL with an amp) and plug them into HU.
5. put radio/pocket combo back in DIN slot and CAREFULLY place bolts in. It's not easy fishing them out (I had to take apart the bottom half of the console, but I DID make $2 off it from a bunch of loose change since the last owner apparently put some in the climate control's pocket, plus the actual reason I did was to adjust the e-brake line)
6. Swiss-Cheese your stock HU at the local shooting range or sell it on EBay.
I did my own install (see CarDomain for my Pioneer DEH-something something

)