New Video Card and RAM for HP PAvilion 533w

.....ok, I'm not intirely new to the inside of a comp, but i have never built one before. Since recently doing a system restore on my hp Pavilion 533w, I've been researching on how to upgrade it and such. I've learned a few things, but I'm not entirely sure i have I get all of it.

How do you know what RAM to buy? What RAM do I buy?

I know that I have four PCI slots, and that there are a few video cards that use it, but what's all this talk about AGP?

Also, i have little to no income, due to lack of job, lol, and i have been checking out Newegg.com for reasonablly cheap cards, but ones that will play games pretty well : I.E. World Of Warcraft, Guild Wars, Half-Life 2

Here are my Specs if they help:
System Information
------------------
Time of this report: 7/21/2005, 05:08:46
Machine name:
Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.050301-1519)
Language: English (Regional Setting: English)
System Manufacturer: HP Pavilion 05
System Model: P9859A-ABA 533W
BIOS: Award Modular BIOS v6.0
Processor: Intel(R) Celeron(R) CPU 2.00GHz
Memory: 254MB RAM
Page File: 169MB used, 456MB available
Windows Dir: C:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode


Display Devices
---------------
Card name: Intel(R) 82845G/GL Graphics Controller
Manufacturer: Intel Corporation
Chip type: Intel(R) 82845G/GL Chip
DAC type: Internal
Device Key: Enum\PCI\VEN_8086&DEV_2562&SUBSYS_80931043&REV_01
Display Memory: 64.0 MB
Current Mode: 1024 x 768 (32 bit) (70Hz)
Monitor: hp pavilion v70s
Monitor Max Res: 1280,1024

 

Any help for this expierenced-noob will be GREATLY Appriciated, Thank you.

:Bows:

 

Look for a FX5500 for around $105

 

I just searched for one at Newegg, but it doesn't look like they would fit in my PCI slots....but hell, they might.

 

Try this:

http://www.newegg.com/Product/Product.asp?Item=N82E16814133134

 

Yeah, I think I've came across this one in my hunt. You really think It'll work/fit or its compatable?

 

http://www.newegg.com/Product/Product.asp?Item=N82E16814139166

OK, i think I've found one.