please suggest some websites to get user guide for wildfire and also how does it work with gaim client
http://www.jivesoftware.org/builds/wildfire/docs/latest/documentation/
Gaim should work as any other jabber client and as with any other jabber server. Though i have seen some issues specific to Gaim, but you should try it by yourself to find out. Setting up an account should be similar to any other jabber server.