Burb, while you are buying tools. Here's a few you'll want to ensure that you have if you are going to work on a GM 3800 vehicle.

10mm, 13mm, 14mm, 15mm, 18mm, ensure you have deep sockets and wrenches both.
3/8", 19mm deep sockets only.
7mm nutdriver
Med phillips and med flat blade screwdrivers

When I say socket, I'm talking 6 point only. With that stuff, you can almost completely disassemble your car.