Need help with PC part compatibility

[Deleted]

Hey guys, I've been on my toaster computer for years and recently my brother has upgraded his PC and sent me some of his old parts.
I'm not very computer savvy And I'm not sure what new parts I will need to complete the build, would appreciate help and opinions on what parts I should get. Looking for a low cost reasonable gaming build.

Parts I received from my brother:

Motherboard
ASUS AMD M5A78L / USB3

Graphics Card
Radeon HD 6850 Direct CU Edition

Processor
AMD Phenom x4 965 Black Edition

PSU from current PC that I can replace if need be:

PSU
TESLA 500T-BR 500W

And case is a CiT Goblin Mesh Case

Would appreciate feedback on what Components I need to go with everything listed, Thank you in advance.

- - - Updated - - -

Bump, still wondering if I'm going to need to up the wattage for my PSU for everything to work smoothly and I'm not sure if the case I've got will be big enough to house all the components in comfortably.

Anybody with a lot of computing knowledge able to help? I think all the sockets and connectors are compatible between these components i.e. Form Factors, SATA and all that.

[acinos]

You could always try http://pcpartpicker.com/ thats what i used to help me build my current rig. Helped me find some good bundle deals as well.

[Deleted]

The only problem is I can't seem to find all the parts I've listed on there, some of them are quite old and out-dated so I was just in need of someone with a lot of knowledge or what parts I should replace and what parts I need as extra (regarding power consumption, compatibility etc).

Please halp =/

[Defaulty]

The first thing you'll want to do is upgrade your CPU. Here is an AM3+ that your mobo will support.
AMD FX-8320 | Benchmark test have it ranked decent. - $145

You'll need to upgrade your motherboard if you want to upgrade anything else. Your motherboard has PCIe 2.0 and any new hardware these days are 3.0.