I set up my first git server with little trouble, yesterday.
There is no single, reasonable book on git, but there's a wiki. The design and implementation are more complicated than SVN or CVS, but it looks useable, and it's the sine qua non of kernel source code management.
In theory, my users could do it all themselves, since git is distributed. In practice, they can't and won't.
They need it, it goes up. And now, they need it.