Sorry, Aine, I misread.

This guy seems to explain things in a very good way, BUT I didn't see anything in a quick scan about rests. He does seem to indicate that a lot of people do not use the same standard symbols for a lot of things, though, so it might be worth your while looking at what he has to say: Tab Basics.

Another site seemed to say that ^ could be used, but I read somewhere else that those are used to pull-offs or somesuch.:-)

Good luck!