Everything JoeB said is correct, but instead of using a .99 paintbrush (snaake's suggestion:-), I *strongly* recommend getting a $0.99 - 3 inch paint roller (the little general purpose poly ones you use to paint trim). We use them at our shop, and they make the process *much* easier than a brush..it'll push it around so much quicker and easier... quick is the key here, if you make too many passes with the roller over too long a time period while spreading, contact cement tends to bead up on itself (little drying balls of CC do not make for a nice flat joining surface..:-) so put lots of it on (a nice steadly pour out of the can -top to bottom of the cab) and work quickly, spreading it out to all edges..
also not mentioned was the need to apply pressure to the laminate after application to create a good solid bond..they sell special hard rubber rollers for this purpose(looks like a small paint roller, made with a rubber roller instead of a fuzzy stuff roller:-), but if this is a one-off thing, just use your hands (one on top of the other and lean into it..) to apply as much pressure as you can to each square inch of cabinet side...especially around the edges, and especially if you had little contact cement balls develop during the application process.. (you don't have to press and hold either, it's not like glue..as long as you apply enough pressure to make the laminate cement contact the cab cement, that'll do it almost instantly)
a router with a flush trim bit, or a laminate trimer all around the edges and that sides done.. you can flip it over and do the other side :-)