I just finished doing this to my 20 year old laminate cabinets. What I would suggest is cleaning them deeply first with a strong cleaner to get off all grease/dirt (something I should have taken more time to do) and then lightly sanding them if you have shiny surfaces. If your cabinets are older and scratched up from years of wear and tear like mine, you could skip this part.
Go to your local Home Depot or supply store and ask them for (if you cannot find it) the Primer you need for this type of surface. There is more than one kind, I bought the super strength one at first made for just this purpose, but the fumes were too intense. I then went back and found a less industrial strength version but still a Primer that read it was to be used for laminate surfaces.
Make sure you apply at least a thick first coat or do two coats. This will help you avoid putting 3-4 coats of paint on top, which is what I had to do on the first set I did a light Primer coat on.
The end result (including new hardwear and handles for the doors) cost us about $120 dollars and looks much nicer that what we had before.