We took off all the doors and washed them with tsp substitute. What I should have done was to dry them off with a towel immediately after washing and rinsing. I didn't and my 20+ year old cabinet doors started coming apart a bit at the seams. It just created an extra step of having to glue and clamp the doors. I also washed the hinges, since they were a bit gross too. I ended up painting the brass hinges black so they would match our new hardware and saved about $80 not buying new ones.
I stripped the finish off of the doors next. I'd skip that step if I did it again. We had to sand everything anyway and we were painting rather than refinishing, so I would just sand and skip the stripper. It also contributed to things coming apart that shouldn't have.
I removed the front panels off of eight of the doors (we made them plexiglass fronted). We had to remove a bit of the inside part of the doors to create a pictureframe-esque door to put the plexiglass into. We trimed it with a jigsaw and then sanded the edges down smooth.
Next we primed all the doors, then painted them with an oil based, white semi-gloss paint. A lot of things I read said that latex is getting better and better for this type of project, but we decided to stick with the oil based for it's durability. There was a lot of waiting for paint to dry between coats (and sides of doors).
Our cabinets doors didn't have handles or knobs, so we decided to add some. I bought black knobs from Home Depot for most of the doors. I ordered glass knobs from a place online for the cabinets that face the dining room. After figuring out where we wanted to put them on a test piece, we measured and drilled all the holes.
We washed, sanded, primed, and painted the faces of the cabinet boxes. I cleaned out the insides of the cabinets, but didn't paint them. Once the paint was completely dry, we put the hinges back on the doors and hung them back up on the boxes.