To find what level missions you can pull,
/tell helpbot level number
Helpbot is unfortunately occasionally wrong in the answer, but is pretty good.
Those of you who can run Perl scripts might like to get one I wrote for calculating mission levels. It is http://www.dd.org/~tale/ao/level . Having used it a lot, I recall only one instance of it being wrong, but I forget what that instance was.
It has three basic modes:
level (with no arguments) -- Prints mission levels for all character levels
level -c number -- Prints missions pullable by that character level
level -m number -- Prints character levels that can pull that mission