There's so much information here, I don't know where to begin; so I'll just ask & hope for the best!

1) There must be a list somewhere to check my current hardware for compatibility? Are hardware drivers (video cards, printers, scanners & audio boards) available? In Linux this can be a real pain!

2) Do I go to Best Buy & purchase the latest Mac OS & install? Is it that simple?

3) If successful, will I be able to update the system?

4) If I purchase genuine MAC software, will it install or will it detect that it isn't a genuine MAC computer?

I'm sure that more questions are to come but please give me a starting point & I'll gladly dig for answers!
Thanks in advance.