New W2K server room

I have to install and setup a new w2k server pool (file servers, DC, exchange server, sms, …) coming from NT4.0. I would like to know, from people who did it, what’s to do and not to do, and have an idea of the ‘real’ (not Microsoft’s) hardware requirements. I would like also to know if I can use an exchange server as DC, or file server as DC. Well, many questions ;o)

If you know very good links to site telling about that all, they’re more than welcome.

Thanks for your help,

NaG