Ok, at the moment I have an ATI Radeon 9200SE graphics card. Good back in it's dy, but for a heavy gamer this card is just a tad out-dated. So I'm looking for a new card, and at the moment the GeForce 6600gt is my favourite option. It's cheap, AGP compatible with my motherboard and can apparently handle demanging games such as HL2 and Doom3 (both of which look shoddy on my system.)
Here's the problem. I know just about nothing to do with computers, graphic cards, the lot. All I know is that my motherboard is 4x AGP and therefore cannot handle PCI cards. That's it. I don't know the difference between the two or anything, just that little fact. Anyway, here is my motherboard, and here is the graphics card I want.
PNY Verto GeForce 6 6600GT AGP8x 128MB GDDR3 (G66600GABF12YPB) Retail Box
Or
XFX GeForce 6600GT AGP 128MB, TV and Dual DVI Retail Box
I'm pretty much certain both of them will work on my motherboard. HOWEVER I have heard that this card is quite power demanding. I wasn't sure how to check the power of my PSU, so I opened my case up and had a look and it seems like a 250W PSU. Apparently, to use this card properly you should have at least a 300W PSU. So here are my questions.
1) Will I be able to run the card on just a 250W PSU?
2) If not, what power PSU do you recommend?
3) How do I find out if a PSU will fit onto my motherboard? What do I need to look for? Or should they all fit?
4) How exactly do I fit a new PSU?
Might seem like a bundle of Qs but I'm really stuck here, so any help will be appreciated.
Here's the problem. I know just about nothing to do with computers, graphic cards, the lot. All I know is that my motherboard is 4x AGP and therefore cannot handle PCI cards. That's it. I don't know the difference between the two or anything, just that little fact. Anyway, here is my motherboard, and here is the graphics card I want.

PNY Verto GeForce 6 6600GT AGP8x 128MB GDDR3 (G66600GABF12YPB) Retail Box
Or
XFX GeForce 6600GT AGP 128MB, TV and Dual DVI Retail Box
I'm pretty much certain both of them will work on my motherboard. HOWEVER I have heard that this card is quite power demanding. I wasn't sure how to check the power of my PSU, so I opened my case up and had a look and it seems like a 250W PSU. Apparently, to use this card properly you should have at least a 300W PSU. So here are my questions.
1) Will I be able to run the card on just a 250W PSU?
2) If not, what power PSU do you recommend?
3) How do I find out if a PSU will fit onto my motherboard? What do I need to look for? Or should they all fit?
4) How exactly do I fit a new PSU?
Might seem like a bundle of Qs but I'm really stuck here, so any help will be appreciated.