As was stated earlier, the best solution is to cut out the old and weld in the new. Even then you have to be careful. New panels have poor primer on them and need to be treated inside and out, and then you need weld-through primer, etc., etc.

Given that the rust seems confined and that you are a poor student, here is what I would do:

--Get access to the panel from inside the car and clean out all the crap the best you can. Scrape, wash with a hose, anything you can do to clean the gunk out.

--On the outside sand the rusted areas until the rust is gone. They will be larger than your bubbling paint--sometimes a lot larger.

--Treat the inside with POR products. Look at the POR web site for details. If your holes are very large you will need to use some fiberglass to cover them. Best is to put soak it in POR then put it on the inside. (If you need to do this send me a note and I will drop some in the mail to you.)

WARNING: Wear gloves. If you get any POR on your skin it is there until your skin cells slough off.

On the outside again, cover the holes and smooth it out using a good body filler. Don't by the cheap stuff at a chain car place. You can get good fiberglass fillers at an auto paint supply store, or online through a number of vendors. The old cheap bondo absorbs water and creates more rust.

Once you have applied filler and smoothed it out you can prime and paint. Rattle can paint isn't that great, but given your situation it will hold for while.

As others have said, be sure not to plug up the drain holes!

Good luck.