There is always stuff going on, but I have noticed people tend to organise stuff in smaller groups, usually by pm or fb. It seems to be if you know people you get to find out about the runs.
The key is to meet folk, let them know you are interested in getting out n about, suggest some places and watch the ball roll.
All you have to do with regards to forums and ride out is think of somewhere you would like to go, choose a date (try to pick one that hasn't got a rally on, as more people will be available).
Start a thread, and ask if anyone is interested in joining you. You can always add it as an event to the calendar so peeps can add themselves to it and can see who is going. Good luck
RB is an expert at organising stuff, so she will have her own tips on how to make it a success.
btw previous post should be Loomies grrr! Spell check!