Working with a new client

Hi recently I’ve taken on a new client who has a W2K3 – W2K AD network…

The current infrastructure is a real mess! and there is no info on how the servers etc are configured.

Any suggestions on analysis tools to check and compile a full detailed report of the network servers/domain structure/computers that will highlight critical issues?
I’ve already started with Microsoft’s best practices analysers, but I’m guessing that a complete scan of everything IT related in this network would reveal some urgent issues…

Just wondering what others might use when taking on/working with a ‘new’ medium sized client..

Cheers
Ernie