It's good to see that IDSAdmin is finally downloadable from the Cheetah Beta download site.
If you are not a PHP head you might find installation instructions in the README file a little confusing. The IDS Experts blog is currently sporting a guide to installing IDSAdmin using XAMPP on Windows. If you are comfortable with having your GUI Admin console running on Windows, following the XAMPP instructions is perhaps the simplest approach to follow, if nothing else because the versions of software listed are known to be compatible.
By the time Cheetah is released, expect installation to be a lot simpler. The goal is a single package that can be installed via PHP. If you run into specific problems with this installation, make use of the Beta support forum so any problems get logged.
Update 3/15/06: Kudos to Unofficial Oninit Blog for the first documented installation outside of IBM: The Installation of IDSAdmin.