Yeah, also learn what makes a good case good. Personally, heres my checklist:
■ Black interior
■ Sleek and as little plastic as possible.
■ Not in excess of 1/5 of the cost of the whole build
■ Cable management holes, preferably grommeted
■ Bigger is usually better, but i like a good mid tower with full tower size
■ I like the option for either 1 big fan, or multiple small fans in the top and side
■ 2 Rear fans is a very nice plus, i favor positive airflow with 2 front fans, 2 top fans, 2 rear fans
■ Has to look good to me
■ I like vents and mesh in select places to help with airflow
■ Removable motherboard tray or cpu backplate cutout is a must, but either is fine
■ Bottom mounted psu with vent on the bottom with dust filter
■ Removable dust filters for as many fans as possible
■ Doors are generally annoying, unobstructed disc drive is the best setup
■ Has to fit an upgrade, so i like ones with futuristic form factor. For now, thats M-ATX, ATX, and E-ATX
■ Well placed windows are good
Thats about it for me, you can generally put a list like this together too, then find a case to match it.