I don't think you're ready to build. Do some research on what motherboard is gonna suit you best and is stable. I don't think there is one that dominates, and waiting you may find something better. Ram you can get from;
Crucial's web promo 15% off first timers
Crucial makes it simple to get the right ram. If you have any questions about ram just ask back. You should use a site like;
reseller ratings.com
to either find good e-stores or evaluate them. They should have at least a 6 for average and at least 100 evaluations to be considered safe. I make an exception once in a while as is the case with
www.icompz.com. They usually have very decent cpu sales.
My advice for a first time builder; Get the best power supply you can (not the highest wattage). Sparkle and Enermax appear to be good choices. Cheap power supplies can start fires, fry you PC, cause instability (that dorks blame windows for). Get the best motherboard you can also. These things don't depreciate like CPU's do. Again for stability, and features. Cpu's you can start out cheap, and either OC them or replace them as prices go down.
I would pick out some components then come back to this forum and have us critique the list. That would be easier than trying to cover everything for you.