Check the Aikido FAQ.
It is one of the links to this website.
There are articles on how to make weapons and how to care for them.
After four years of use, I just put a clear varnish over mine, and they are quite pretty again. Plus I just made two bokkens from axe handles to get the weighted feeling when practicing sitting between downloads ...
Don't leave your weapons where they will warp and bend from the heat, and on a flat surface would be the best. We had a new guy who had done Aikido four years before who left his bokken in the closet, it was bent hard over to one side ... quite comical for thrusting. I let him use my old bokken until his was replaced.
Go read the FAQ (Kjartgen? My spelling isn't the best.)