If you want some help with getting started, Ubuntu Bug Control has got a mentoring program designed for getting people acquainted with triaging. At BugSquad/GettingInvolved is explained how to request a mentor:

• sign the Code of Conduct
• Although not really required, read the How to Triage guide. It does help to read it 
• request a mentor, via an email to ubuntu-bugcontrol@lists.launchpad.net. In this email, please provide an area of specialisation, if you have any.

I would like to add that including the username of your Launchpad account is most helpful as well, since that makes it easier for us to scan what you’ve done so far.

As always, questions can be asked at our IRC channel, #ubuntu-bugs at FreeNode.

If you’re already quite familiar with triaging and want to help new people, you’re most welcome! Please sign up as a mentor by leaving a little note at the ubuntu-bugcontrol mailist and add yourself to the list at BugSquad/Mentors. This page contains also more information about what is expected of you.