In addition to what ciscooderator said, you
might want to check out the following resources:
Book: Cisco IOS Network Security, put out by Cisco, has scenarios and commands for TACACS+ deployments.
But of course, since you're online, you might want to check out the security tech-tips page.
http://www.cisco.com/warp/public/707/index.shtml
Your post didn't have a lot of detail to it, so I have no idea what you want to do with TACACS+ - suffice to say you can do quite a bit with it :-)
Hope this helps
-Rakesh