First time upgrading; Need some help

[Patbehr]

Hello everybody, my name is Pat and I'm working on my first computer upgrade!
I have some questions I wanted to get answered before I actually put anything together.

I'm getting 4 new pieces; A motherboard, graphics card, power supply and CPU.
I already made sure the motherboard and gfx card are compatible (AM3 slot for an Athlon II cpu)

This is the motherboard I'm considering:
ASUS M5A78L-M LX PLUS

Graphics card:
Nvidia geforce 8400gs (512mb, GDDR 2)

CPU:
Athlon II X4 640

What kind of power supply will I need to run all of these?
Will they work together?
Do I need any additional items?

I will post additional information about each item if needed, but I have to split for now. Any info is greatly appreciated! I don't wanna fry anything, haha

 

[cavemangrinder]

For the power supply, I'd go with a good brand 350w or so. Shouldn't need much for that gpu.