Different motherboards have different sockets, which changes the range of compatible processors. Your motherboard essentially determines if you can run the lower-cost but decent powered processors to the very expensive but server level CPUs.
The importance of a higher wattage supply is mainly upon the fact that the computer would use a higher amount of power. If you're going to upgrade it, 500Ws would be a general mid-range between the "Not too low to the point where my computer can't even turn on" to the "So high that I can run 5 Hard-Drives and 3 CPUs in a single computer case, and my electricity bill quadruples"
I don't know what kind of graphics cards YOU should get, since different cards have different compatibilities, different costs, different performance/memory, etc... If all you're going to do is some light work and Toribash'ing, all you really need is a graphics card like this:
EVGA 512-P3-1311-KR GeForce 210 512MB 32-bit DDR3 PCI Express 2.0 x16 HDCP Ready Low Profile Ready Suggested:
SAPPHIRE Radeon HD 5570 100293-2GL Video Card
RAM is "Random Access Memory." It's basically (for a lack of better terms) the computer's short-term memory. It gets cleared often (mainly when you shut down), and is used for programs to store specific pieces of data for quick access. It's significantly faster than normal Hard Drives. For example, if I were to run a graphics intensive game, much of the character data that has been viewed (if I pass by high-detail scenery) and/or compression/decompression information would be stored. The RAM offloads the data to the graphics card and CPU quickly, so if you were to have to load it again, it's ready at hand for the computer.
Last edited by LastGod; Apr 28, 2011 at 07:32 AM.