I live in a house that was built in the 1950's. It has wooden kitchen cabinets that have been painted from the looks of them alot of times. I know I have painted them twice. Every time I paint them the paint comes off in some spots you can actually peel it off. Then around where the handles are they get all scratched up and you can see the old paint. I'm using a semi gloss paint. I want to paint them again. Can you please give me some advice on what to do. Or what I am doing wrong? I really want this to be the last time I have to paint them.
To get something that lasts on high traffic touch areas like cabinets you need to go with oil based paint. The latex stuff just doesn't hold up and it will come off or get rubbery with water, changes in temperature (near oven), or a lot of touching (oils and rubbing it). This is especially true when latex is on oil without being primed right.
If the cabinet doors are nice I would try to strip them. A more practical solution is buying an oil based primer made to go over latex. And then an oil based paint on top of that. Do your worst offending door. See how the results are after a few weeks or a couple of months and then do the rest.
You want to get off the latex paint as best you can. Using a stripper is likely safest given the chance there that one or more layer is a lead paint and therefore a risk if you're sanding.
Use a high quality primer, probably oil based (certainly oil if you use an oil top-coat), to ensure it sticks well.
If you can strip it down to the bare wood, you might be able to get a latex paint to hold up if you give it several days to fully dry before exposing it to heat and humid environments that are the norm in the kitchen.
Oil paint will harden more quickly and hold up to a bit more abuse. Remember to ensure plenty of ventilation while working and for several hours (days) after you paint. People who have only painted with recent low-VOC latex are often surprised during their first experience with oil paint (same applies to many but not all strippers but people expect that more).