Refinishing rough veneer on kitchen cabinets
I'd like to do some work on our kitchen cabinets to protect them. We just bought this older house a year ago, and this is my first experience with unpainted wood cabinets. The doors (particleboard), drawer fronts and face-frames (plywood) - are covered with a wild-grained oak veneer which was stained a orangeish colour. Some surfaces are still smooth, but most of the doors have a slightly rough texture (when I brush my fingers across the grain) which I think indicates the finish has worn off at least partly. Also, most of the doors had lots of fingerprint stains which I've mostly been able to clean off. I think its been years since they've had any attention.
I'm wondering if there are steps I can take to further protect the surface? Could I just put some polyurethane or some other finish on the doors, or do they need to be lightly sanded first? Should I wax them or something like that? I'm not sure what the current finish is. We'll eventually replace the doors or even all the cabinetry, but other parts of the house need more attention. So, I'm looking for suggestions on how to protect the surfaces over the next 5-10 years. Happy to do the work, so long as costs are relatively minimal.