I'll throw in another recommendation for NewEgg. Also, to start you off, go to ArsTechnica to do some research into what components are good and how to put it all together.
Here are some recommendations I can offer as I've built a PC once as well:
AMD processors are better than Intel's processors price-wise. There's a nice explanation at Ars Technica.
Compare those prices to Intel's. It'll be a minimum of $116 for a Pentium 4, and that's assuming you go with the low end 1.8 GHz model. Faster ones are quite a bit more expensive. Their clock speed may be higher than an AMD, but we know as Mac users that clock speed isn't everything!
IDE cables are included with the motherboard. You can go with a cheap motherboard if you want, but the motherboard is important. A lot of PC manufacturers save most of their money by going with the cheapest, worst motherboard available. There are various features you may want - built in ethernet, onboard video (if you won't be doing gaming, that is), USB 2.0, good integrated sound, AGP 4x vs. 8x, overclocking ability, and so on.
It's funny... I love speccing out PCs and looking for all the best components to meet a certain price while still maintaining quality and style. But I don't actually like PCs. They're no fun to use, just to make. So good luck making yours, I think it'll be a positive experience. I had never built a PC before myself and it wasn't too hard.
Here are some recommendations I can offer as I've built a PC once as well:
AMD processors are better than Intel's processors price-wise. There's a nice explanation at Ars Technica.
Compare those prices to Intel's. It'll be a minimum of $116 for a Pentium 4, and that's assuming you go with the low end 1.8 GHz model. Faster ones are quite a bit more expensive. Their clock speed may be higher than an AMD, but we know as Mac users that clock speed isn't everything!
IDE cables are included with the motherboard. You can go with a cheap motherboard if you want, but the motherboard is important. A lot of PC manufacturers save most of their money by going with the cheapest, worst motherboard available. There are various features you may want - built in ethernet, onboard video (if you won't be doing gaming, that is), USB 2.0, good integrated sound, AGP 4x vs. 8x, overclocking ability, and so on.
It's funny... I love speccing out PCs and looking for all the best components to meet a certain price while still maintaining quality and style. But I don't actually like PCs. They're no fun to use, just to make. So good luck making yours, I think it'll be a positive experience. I had never built a PC before myself and it wasn't too hard.