another tip - buy quality components. the most frustrating part of building a computer can be dealing with faulty hardware. look at reviews on tom's hardware, or system guides one
www.arstechnica.com (or similar sites) to help identify what brands to look for.
there's nothing quite as aggravating as putting everything together and then having your computer fail to boot because of a faulty motherboard.
ymmv, but i have heard of as high as 30% return rate at fry's on their cheapest motherboards.