Under 1000 first time build

New amds and intels are coming out during the next couple months (amd yesterday, intel today, more to come), so you could wait and check out the new amds. Amd is the way to go at your price point.

AMD 720x3 BE Triple Core~139$US
http://www.newegg.com/Product/Comb [...] mbo.190879
Asus 790GX~139$US
http://www.newegg.com/Product/Comb [...] mbo.190879

Combo~258.99$ with 15$mir

Gigabyte UD4P 790X~110$US
http://www.newegg.com/Product/Prod [...] 6813128387

Here's a start. They use to offer the 720 with the gigabyte mobo on newegg, couldn't find, try again later.

Given your budget, it would be hard to choose a good intel cpu. Right now AMD is the best choice from $85 - $250. Beyond that, its i7, which although better, really isn't worth the money, not when it comes to gaming and simple tasks.

There is the Phenom X2 550 BE, excellent dual core for just $100, then the Phenom X3 720 BE, my favorite since its three cores, for just $140. Then there is the Phenom X4 940 BE, at just $190, and a step up further than that is the Phenom 955 BE at $250. All the best choice for the money.

Its really up to you depending on how many cores you want. If you wanted intel that badly, you could wait on the i5's which, from what i've seen, are going to be very good. They will probably push AMD back down. There is the 2.66 GHz i5 coming for just $196, and is supposed to equal the i7 920 in most ways, plus p55 boards are probably going to be cheaper than the x58 boards, and they will only use dual channel memory.

That's my input.

With your budget, you will have no problem building a very good PC.

For multitasking, the first thing you need is sufficient ram to hold all the active tasks. Fortunately, ram is relatively cheap these days. I would suggest 4gb at a minimum, and perhaps 6gb or 8gb.

To access more than 4gb, you need a 64 bit OS. Vista home premium 64 bit is fine, but consider installing the release candidate of windows-7 64 bit. You will need to do a clean new install of the official release in the fall. If a re-install is a problem, then just stick with vista.

Normally a multitasking system would call for a quad core cpu. In this case, I do not see the multitasking as being particularly cpu intensive, so a highly clocked duo like the E8500 could also be good. For a quad, a modestly clocked quad from Intel or amd is probably all you need. The new i5 cpu's are due out in the third quarter, maybe, and they look good. Can you wait? They might not meet your August timeframe. I would wait until the last moment to act.

Gaming performance is primarily determined by the power of the vga configuration. This is more so if you will be using a higher resolution monitor like 1920x1200.
Something like a GTX275 would be very good for most games. In the 4th quarter, there should be another generation of 40nm vga cards out. To protect your investment, I would get a card in August from XFX or EVGA or anybody that has a 90 day step up trade in program. Unless gaming is your #1 priority, and a GTX295 is not good enough, don't spend extra to provide for sli/crossfire.

Spend some time finding a case that suits you. Read the reviews. Download and read the case installation manual. It will tell you lots of what you need to know about building your PC. For what it's worth, I have had good experiences with Antec cases.

In a similar vein, download and read the manual for a motherboard that you are considering. They usually give good instruchtion on how to connect things up.

How much hard drive space do you need?
If you need <300gb, splurge on a WD velociraptor. It will make everything seem quicker.
If you need >300gb, look at the WD caviar black 1tb drive.
Prices and performance of SSD's are improving rapidly, but it will probably be the end of the year before they become mainstream parts.

Do not skimp on a psu. Good quality units come from Corsair, Seasonic, PC P&C, Antec, to name a few. The wattage is less important than the 12v amps. How much you need is determined by your vga card.

---good luck---