Although there are list of programs included in UBCD at http://www.ultimatebootcd.com
and at http://wiki.ultimatebootcd.com/index.php?title=Tools
, I don't think there is much difference (between UBCD versions) about how to start a certain program. Form those pages you can also get to several different additional information about UBCD.
For each program, you should search for each manufacturer's web site, and you should already know what you are doing before using it.
About antivirus tools, there are a couple of scripts to update the antivirus tools (included in PartedMagic, included in UBCD), but if you have problems knowing how to use UBCD, you should probably better look for a solution focused on security (SARDU for example, among MANY; or some on line scanner, or some security-focused forum).