I would recommend checking this web site. http://www.hardware-revolution.com/
When I had no idea how to build a computer, this was a pretty good starting point. Specifically, check the "Best parts for your money," and "Mainstream gaming PCs" section. These two sections basically do what you're asking for in this thread, and it's updated fairly regularly. Once you know more about computer parts, you could always substitute parts they recommend and decide what yourself what's best for you, but I still find it to be a nice reference even if you know what you're doing.
If you need to compare parts like cpus/gpus, look for reviews of them online and check the gaming benchmarks in those reviews. http://www.anandtech.com/bench/CPU/2
is also a nice tool to use for quick comparisons.
Aside from that, read computer forums. I personally use http://www.overclock.net/
and learned tons about computers there. There's sub forums for every single part, and people post about builds they're going to make on the general hardware forums, as well as the intel and amd general sub forums.
If I just gave you way more information than you needed, simply check the first link I posted, it'll answer your question. Oh, and just a tip, you can easily build a PC that will run this game for way less than $1500 if you'd like to save some cash. Though if you want a more powerful one for other/future games or just like the idea of being able to play on the highest settings with blazing fast FPS, go for it, your call.