Dual boot...?

Hi all.
How do you dual boot windows and linux? I would go for just linux, but as far as I know, macromedia doesn’t support it. So I would use linux for most things and then windows for flash, fireworks etc.

Can anyone give me a step-by-step guide? I’ve scoured the internet for info, but nothing is in plain english.
Also, what (free) linux OS can you recommend?