What Certifications are needed? How to get them

You may be of some help, I have an odd situation. I am already the Technology Coordinator at a small charter school. We have approximately 100 desktops/users, a Windows 2008 server, 2 Windows 2003 servers (one is file server, one is SQL), and I am the only guy here. Believe it or not, I installed/set up/run/troubleshoot all of this myself, no official certifications. I also teach web design using MS Expression, and a VB.Net course (very basic). I basically want the paperwork that says, yes this guy can do this. Not sure if I need to actually take courses, or purchase books, or what courses to take. I am taking A+ cert myself with just a book, took practice tests and passed with ease. Any help is much appreciated.