For those of you with cabinets that have finishes that are less than pristine, but not bad enough to justify a total strip/stain/shellac or varnish, this is what I do with my cabinets:
I went and bought "Howard's Restore-A-Finish", and a bottle of "Howard's Bees Wax and Orange Oil". It's very easy to use, you'll need some 0000 steel wool, and some soft rags. When you apply the R-A-F, use the steel wool and make sure to follow the grain of the wood...rub gently. Wipe the wood down, and I let it sit for a bit...just to make sure it's dry. Take a soft rag, put some of the beeswax on it and rub it onto/into the wood. You're going to leave a pretty good "film" of it on the wood and allow it to sit and soak in for at least 20 minutes...I let it sit overnight. Take clean, soft rags and wipe the excess wax off, and another clean rag to buff the wood to a beautiful glow.
It's not going to take out mildew (those dark stains from using the cabinet as a plant stand) but it will help the finish, and even if you need to strip it the wax/oil will help to preserve the wood until you can get to it.
Needlebar has an excellent tutorial on refurbishing wood done by Fenman...I don't know if you have to be a member to access it or not, but here's the link: http://needlebar.org/main~nb/restoration/index.html