I'd be glad to tell you more about what to look for. Add Whiffen to your steam friends list.
I was writing all the information out here but after 100 paragraphs I think it was beginning to be to long. (Screw it I will post it anyway XD)
Processor:
For processors you have the big two, AMD and Intel. Intel holds the lead for fastest line of processors, however while AMD can't fully compete with Intel's fastest they offer very good value for there processors, great for anyone with a tight budget. AMD's flagship is 5x cheaper than Intels flagship, and only 10%-30% slower in most benchmarks, sometimes even matching Intel.
In gaming performance where multi-threading is still quite new this difference in speed is defiantly not worth the extra cash and more for those who do video encoding, rendering and other CPU heavy stuff or has cash to burn.
If your buying from AMD look for the Phenom II line. Then look for either X2, X3, X4 which tells you how many cores it has. Lastly you will find a number at the end which tells you what speed the processor runs at. I would highly recommend above 2.5 Ghz and aim towards the 3Ghz+ range. Now remember not all things are multi-threaded, meaning not all cores will be active or at there full potential. This means a dual core running at 3Ghz is not equal to a 6Ghz single core, or a quad core at 3 Ghz is equal to a 12Ghz single core. The processors will never run over there rated 3Ghz. Socket AM3 is the newest and supports all the Phenoms. Phenoms are also backward compatible with AM2+ boards but those don't sport support DDR3 memory.
From Intel I would say there Core2Duos are a nice budget processor but Intel has since abandon there socket 775 LGA line. This means any newer processors from Intel will not use this socket type. Thats OK if you don't ever plan on upgrading, but if you were planning to one day then you would also have to replace your motherboard and memory as well as the processor. The new socket types are LGA 1156 and LGA 1366. The later of which is only for i7 processors. LGA 1156 is what you would be looking for but unfortunately these motherboards are more expensive and use more expensive memory. The goal for a budget system is to spend the most on the CPU and GPU as these are the powerhouses of your computer and to spend so much on the motherboard and memory doesn't seem as reasonable.
Anyway the i3 and i5 lines of processors are what you should be checking out. (I hate this stupid putting "i" in front of fucking everything fad XD)
Motherboards:Whew. Now motherboards the main two are ASUS and Gigabyte. Both are great brands and they have similar specs and prices. You don't want to go dirt cheap with motherboards like most prebuilding manufacturers slap on there computers to lower the prices. About 80$-100$ is good. When you buy a more expensive motherboard your not getting a lot of extra speed from it, most people do so for the extra features like higher overclocking ability, more options for voltages and other nice features. Almost every year a new model is put out in the same price ranges as last years model so just look for the newer ones as they are just an upgraded last years model with different features more power saving options and other nice things.
For ASUS AMD you will see something like M4A77TD. M is AMD socket types, 4 is the generation, next year it will be 5, A means an AMD chipset, the other would be N for and integrated Nvidia chip set. Chip sets are like an onboard video card. They are there to output information to your display and transfer information between the CPU and memory and also connect every other component. Some are more powerful than others but they all generally suck balls when it comes to running graphics and you will be buying a dedicated GPU anyway so it shouldn't matter to much to you. They are good for people who need to run Win7 and Vista at full visual settings and play 2D games but thats about it. 77 is the chipset model, in this case an integrated AMD 770. No idea what TD means and to lazy to look it up lol. Sometimes you will find a -E, -M or something at the end. This can indicate Energy saving, Micro ATX which is a smaller sized motherboard among other things.
ASUS Intel same story. P for Intel, then the generation, currently 7. Then a Crazy naming scheme for the chip set from P to Q to T xD But again, the 775 models fit with the AMD board prices starting at 80$-100$, the new socket type however breaks out of this loop and starts at almost 200$, which when building a budget rig seems pretty tight.
One you picked a nice board that comes with everything you need, which most will as 1 PCI express x16, (Graphic card slot) a few PCI slots for general things like a wireless card and many many SATA ports for newer hard drives and DVD drives are pretty standard.
Memory:Now you look at what memory types your board supports. DDR2 is pretty standard these days and as such is a bit cheaper than the newer DDR3, however AM3 boards only breath DDR3. Any speed thats supported is fine, DDR3 very fast and the differences between them are negligible. So find one with a good price and lots of nice reviews, try to stay away from the cheap lesser known brands. OCZ, Kingston, Patriot, Gskill, Corsair and Crucial are all fine.
Look for DUAL channel memory, not Triple as those are for the i core Intel boards which have 6 memory slots not 4. Last thing to look at is CAS latency. You might think wait these two memory sticks are at the same speeds but this one is 40$ cheaper!?! Its probably because the cheaper one has a higher latency than the other.
Video Card:For the video card ATI/AMD is really doing well and have finally pushed Nvidia off the performance thrown. ATI is kicking ass with DX11, sweet prices and lower power consumption. Nvidia is struggling to get out there new cards out and have mainly just been rebranding older cards. Look for any HD 57-- card or even better a 58-- card. A 5770 or 5850 is more likely to be the card in your range.
Power supply:Lastly the PSU. I would say 600watt or maybe even a 500watt would be more than enough. Perhaps even higher if you would lake to have some headroom for a later upgrade. You don't want to go cheap with a PSU, get somthing decent and dependable. Antec, Corsair and OCZ are good. What you then want to find is the Wattage on the 12v rail. This supply's power to your DVD drives, hard drives, graphics card and CPU so its important to find one with good power. You might see 12v1, 12v2 and more rails. This is because a law was passed which stated the maximum amount of power each wire can have safely running through it, so it doesn't heat up and burn your house down.
http://images17.newegg.com/is/image/new ... 05?$S640W$Look for 12v+ and look under you will see it has 60A available. This is a very good amount, much over what you will need though. You can also sometimes find "Max combined wattage" on the PSU and it will tell you what rails this applys to.
http://images17.newegg.com/is/image/new ... 06?$S640W$In this you see 12v1 and 12v2 both with 22A. You could assume this PSU must have 44A on the 12v rails. However you can see underneath that only 423w of the PSU's 550w is available to those rails. In brackets you can see that really the maximum you can have is not 44A, but actually 36A. If it doesn't tell you the amps in brackets its a quick calculation, just divide the available watts by 12 (12v rail). 423w/12= 36A.
On the safe side I think 30A is enough. People tend to buy more watts than they need. This calculator is saying a 300 watt PSU is enough to run the above setup but I think 500w would be on the safe side.
So to update the list at the top
http://www.newegg.com/Product/Product.a ... 6819103471http://www.newegg.com/Product/Product.a ... 6813128392OR:
http://www.newegg.com/Product/Product.a ... 6813131603http://www.newegg.com/Product/Product.a ... 6817341017 Also I chose those because of the prices after the sales. It all depends on what you can get for yourself wherever you live. That PSU is a good deal for you price range on sale, however if you can't get it at that price and its over 100$ your spending to much.
I'm going to stop typing now XD