Managing windows server 2003

I have a bunch of windows servers running an intranet based application on it. It is an IIS based application. I would like to know the ways to manage/maintain these servers. A few things that I could think of are patching, checking disk space, space allocation etc. I would like to know if there are any articles or white paper which could describe the ways or things to check the successful running of a windows 2003 standard server. These servers are running Sp2 on it. Once I have all the parameters defined, then I would create relative scripts for them to run the tests regularly and trigger emails after every test with results. Appreciate the help.

Thanks
Prabhat