1. "Sapphire 5870 Eyeinfinity 6 edition 2GB GDDR5 PCI-e ( apparently this is a pre-built crossfire card, meaning it is like having 2 Radeon HD 5870's from what I'm told?<--comments are more than welcome on this I don't actually know. I told them I wanted the x2 though.."
sorry to say that the 5870 is a single gpu card. the 5970 is the dual gpu. the 2GB GDDR5 is the memory size which should help out on gaming but not as much as if you had the 5970 which costs an arm and a leg if you can find one.
2. "Ram: Corsair dominator 12Gb DDR3 ( I'm pretty sure it's 2 sticks of 6GB but it might be 3 sticks of 4GB)"
if you have a core i7 processor, then you should be running it in triple channel mode which means you need 3 sticks of 4GB for 12GB -or- 6 sticks of 2GB for 12GB which are usually sold in 6GB kits(3 sticks of 2GB). if you have 2 sticks of 6GB, then are running in the slower dual channel mode which core i7 chips can run in but are not optimized for.
3. WD 1TB (32Mb) Sata 2 HDD 7200rpm
"WD" means Western Digital which is the brand name
"1TB" means 1 Terabyte or 1 Billion Bytes. This is hard drive space for your movies, pictures, and music.
"32MB" is the cache memory. Cache is a component that improves performance by transparently storing data such that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere. If requested data is contained in the cache (cache hit), this request can be served by simply reading the cache, which is comparably faster. (wikipedia)
A MILD WARNING - chances are you bought the system from a boutique or other electronic store. They almost never supply computers with dual hard drives. This means that if your hard drive fails you may lose everything you put on it. If you get the chance, install a smaller hard drive, preferably an SSD around 80GB, to hold your operating system, program installs, and pc games then use the 1TB for saves and storage so if anything goes wrong, you wont have to worry about losing any music, pics, vids, or documents saves.