How to Decide Gaming card for my PC ?

Hi all :bleh:

I am Looking for a Gaming card for my pc so that i can play Games in a better way.
while browsing this forum i came to know that there are many factors which one need to look into. like power supply, slots available on motherborad, blah blah....
can u guide me which points should i consider before buying one for me :biggrin:

See here http://forums.techarena.in/guides-tutorials/1049244.htm
http://forums.techarena.in/video-games/1086896.htm

See this guide for more reference : http://forums.techarena.in/guides-tutorials/1060536.htm
http://forums.techarena.in/guides-tutorials/1110881.htm
http://forums.techarena.in/guides-tutorials/1093105.htm

Or you can have a look at the Guides & Tutorials for more knowledge .