Which Computer Components Need To Be "Compatible"

[SRF]

Hey everyone,
I was planning on slowly upgrading my computer, starting with my PSU, then the motherboard, processor, video card, etc. However I'm not 100 percent sure on what needs to be compatible with what. So I'll state a list of parts, and what I think...mabye somone could add or correct me? Thanks...

PSU - No compatiblilty except, 24 pin and a good quality?
Motherboard - Compatible with processor
Processor - Compatible with motherboard
RAM - Compatible with motherboard
Video Card - Compatible with motherboard?
Sound Card, Optical Drives, Floppy Drive and hard drive, dont need to be compatible? (Considering the motherboard supports both SATA2 and IDE)

SO generally, I was wondering if those are the things I need to keep in mind. I don't want to upgrade and mess anything up, not realizing that it had to be compatible with another component.

Once again the sum it up, is this list correct, or did I miss something having to be "compatible" with something else, in order to upgrade it..

Thanks for your time, hope I made this clear enough

 

[Geoff]

Seems like you got everything right. I would get the motherboard first though, that way you know what will be compatible with everything else.

If you're looking at some newer and more expensive motherboards, some require an 8-pin CPU connector instead of the traditional 4, so thats something else to watch out for.

 

[computermaineack]

That's about correct, however, I'd suggest that you upgrade all at once...you'll probably run into problems with Windows switching out some things like the processor, Harddrive, etc.