First off, let's talk Brands. Buy Western Digital, HGST (WD rebranded), or Toshiba, as they have the highest quality and lowest failure rate over time. Don't buy Seagates, as their failure is 8-10 times higher than the previous two.
Next, interfaces. SATA has three variations: SATA I, SATA II, and SATA III (AKA, 6.0gb/s). Most drives nowadays are SATA III, but not all motherboards support SATA III ports; they just have the slower SATA II's. If you know your motherboard has SATA III ports, be sure that it's plugged into the SATA III hard drive. Otherwise you have bottlenecked speeds.
Installation is easy. Honestly, you just connect the SATA cable, SATA power cable, toss it into your rig, and turn it on. Then you need to run Disk Management in order to format the drive for your usage. You can find guides for that online.
Lastly, price. For your purposes and size, the Western Digital Red and WD Black series are good. Get the
2 TB WD Red if you want a good, large, stable drive for a good price. If you want faster and have an extra $30 to spare, get the
2 TB WD Black. If you have a Newegg account, watch their newsletter for coupons, because hard drives are on sale quite often.
Also, you will need a SATA cable. All SATA cables are cheap and reliable, and there's not really a difference between them. Pick the one that's cheapest with the best ratings and is as long as you need it to be. Having a right-angle plug is a plus, too.
Hope that all helps.