First - if you walk in the recruiting centre, full disclosure. Tell them everything and don't hide anything.
Second - not to diminish the offence (what you did was wrong, and I see you admit that) but that would probably be considered a "minor" offence. When I was in recruiting, the rule was that a person had to be clear of any judicial obligation for at least a year before beginning the recruiting process. Rules might be different now, and so the best advice I could offer is to call the recruiting centre, explain your situation as you did here, and ask them - they'll tell you.
If it still applies, though, in your case this would be a year starting when your fine / community service has been paid, or your probation period is over, whichever is later. So you're going to have to wait a while. It may hurt your chances of getting in, but it may not.
The key will be your attitude:
Jester said:
I accept all responsibility for my actions.
As long as you demonstrate this attitude throughout the process, and are completely honest, forthcoming, and open about everything, you'll still have a decent chance.
All this said, I'm going to be blunt. We're in a life-or-death business here, and the last thing we soldiers want to see is someone coming in who has a problem keeping his hands off others' kit. In certain circumstances, the consequences could be fatal. So before you apply, ask yourself some hard, honest questions about your character... If this is a problem for you, and you have a pattern of doing this (although you may not have been caught in the past), then please do us, the CF, and yourself a favour - and don't apply.
However, if this truly was a unique moment of juvenile stupidity (and we've all had those in various forms :blotto
then pay the fine, do the time, don't do it again, and give the CF a shot when you're clear.
Best of luck, and feel free to ask us any other questions. Hope this helped.