Nmap Questions :(

I'm on a network, with a fair amount of users. I was wondering if there was a way to scan the entire network, and get detailed information about any users on the network.

I've been looking at nmap and I read (skimming) most of the tutorials on here so I googled it and hit the nmap docs. It scared me :P. So I was also wondering if there was any good tutorials anywhere else on nmap and if there is any alternative tool for what I am looking for. Thanks :P

Robyn