Need a new graphics card.

[ohidentity]

I'm extremely uninformed on the subject of building PC's and replacing parts and what-not. I'm looking for a new graphics card.
http://www.newegg.com/Product/Product.aspx?Item=N82E16883113119
This is my PC. It's good, it's just that the graphics card isn't very good. It's got a Geforce GT220 which is average, I'd say. What I'm wanting to know is what are the exact technical aspects that I need to look at? I know not any graphics card can fit into any PC, so that's where I need help.
http://gizmodo.com/5569723/the-best-graphics-cards-at-every-price
And I'm gonna be using this website as guidance.

Thanks in advance!

 

[Marshillboy]

I'm afraid that 300W power supply will not be able to handle a much better video card. You will have to upgrade the PSU before you do anything else.

 

[Atomic Rooster]

You need to know what slots are available and the size of the power supply. Looking at the specs, it has a PCIe x16 slot for a video card and a 300W power supply. Most of today's high powered video cards require at least 450W and higher to operate properly. So you'll need a new power supply to go along with a new video card.

 

[ohidentity]

Okay, so if I bought the Radeon HD 5750 I would need "450 Watt or greater power supply with one 75W 6-pin PCI Express® power connector recommended" (Google).

Could someone link me to this power supply? Sorry I'm so nooby when it comes to this...we all gotta start somewhere, right? Haha.

 

[Atomic Rooster]

I would suggest these:

HIS Radeon HD 5770 (Juniper XT) 1GB

COOLER MASTER Elite 460 RS-460-PSAR-J3 460W

 

[ohidentity]

Ah, thank you. You've been a big help. How hard is it to install? I'm assuming it won't be too bad...

 

[Atomic Rooster]

The video card is pretty easy. The power supply is a little more involved because of all the connections. If you're fairly handy with a screwdriver, you shouldn't have any problems.