Take a look at David Blank-Edelman's Perl for System Adminstration for a good set of Admin tools. Dave covers both Unix and Windows in the book, and it's worth reading the sections that cover the 'other' operating system (which ever OS you aren't using) to get a perspective on a different way to approach the fundamental challenges of the SA's job. There are a lot of 'out of the box' solutions in the book and it provides enough basic information to act as a spring board into the deeper end of the SysAdmin pool.

Highly Recomended, Bear-Bob says: "Check It Out"