The basic rule of thumb we use is only bump an old topic if you have something relevant to say that hasn’t really been said before.
I typically follow a simple process if I feel like I’m bumping an older topic: if what I have to say isn’t more than, say, two or three sentences, it’s not important enough to revive a dead topic. That’s just the procedure I use, though.
The most important thing about bumping an older topic is simple, really: use your judgement. If you feel like what you have to say isn’t going to do anything significant for the subject, don’t post it. There’s no point in reviving a topic to say something that is just going to get lost in the sea of posts in a few days anyway.
All that said, it is good to see a new member try to get some activity going on around here.