Nice job, especially considering you just started.
FYI, the CPU is the Processor so you already have one picked out. As for the PSU, a good 650W should do the trick. I would suggest a PSU from Corsair, OCZ or Seasonic, maybe Antec - I would suggest a Bronze rated PSU (there are Silver, Gold and Platinum rated PSUs too but I feel the cost isn't worth the added efficiency). And anyone who has built computers for a while will tell you that a good PSU is crucial, so don't skimp out.
As for the case, you're the one that will be looking at it, so it's really more your preference. Start with ATX mid-tower cases - it's a standard size and should fit any motherboard. Ideally you want good ventilation and airflow. Personally, I try to find cases that have front, side, top and rear fan vents (you don't have to fill all of them, but I like having them available if I need them). Another thing to consider are the ports. I usually look for USB 3 which should be standard on all the newer cases. Also, depending on where you'll place the computer, the location of the ports can be factor. For example, a computer sitting on the ground should not have ports located at the bottom of the case - dust will quickly accumulate and render the ports useless.
for starters - you can filter to your price range or other preference. Amazon
is another place you can check.
Instead of the 660, maybe the 650 Ti Boost
would be a good alternative. It's cheaper and very competitive with the 660.
One last thing, Haswell just came out, so compare those CPUs with the Ivy Bridge you selected. If they're similar in price, you might as well go with the newer technology (just keep in mind you'll need to choose a different motherboard too).
Hope this helps.