Some1 plz help im new to this kina thing

hihi
my comp is pretty rubbish, it has:
Intel Celeron processor
2.3GHz
80GB
256MB RAM
IM845GL Motherboard (<- no idea what that means )
Intel Extreme Graphics

I was just wondering what i would have to do to get World of Warcraft to run descently, it runs ok in low pop areas atm with Intel Extreme Graphics, but still i cant play the full game cos i lagg to much in places where i dont want to lag, which is usually everywhere. I was thinking of buying a new Video Card, but ive had a look and most good ones say they wont run on anything less than a Intel Pentium 4.

Can some1 plz recommend a video card where i can at least play world of warcraft better than i am already, i am on a budget tho Also would i have to buy a new motherboard to support a new viedo card, aswell as a socket or something? ;p i no i shud probs get a new processor aswell, but then i guess it wud be btr buying my own comp. Can some1 plz tell me the cheapest way of decreasing my lagg on World of Warcraft, as thats all i care about

Thx for ur help

p.s links wud help aswell as price quotes,

i just looked in my motherboard mauel, and it states -

Your motherboard offers the following features
- Intel Pentium 4 processor in the mPGA 478 pin package
- etc.

does this mean my motherboard will support new graphics cards which have the pentium 4 requirements regardless of me having a celeron processor?
or
can i just buy 'pentium 4' and a new video card and hope that it will work?

im guessing ppl no, but just cba to tell me *runs off crying*