Just getting back into pumping after a long break. Mostly just been pumping in town while getting from A to B, but planning on doing longer distances this summer. Here's some info based on my own experience, hope you'll find some of it useful. 'Scuse if some of it is obvious, just happy to see people interested in pumping, and OP asked for intro info.
* I've only ever pumped on topmount setups. I suspect topmounts are easier to learn on, since you can have your front foot on top of the truck, and don't have to worry about hitting the wheels with your front foot. Topmount setups can have very squirrely front trucks, so it's good to go easy first, fe. see how it feels like to steer with one foot when pushing or foot braking.
* Short wheelbases are easier to pick up initial speed on, and perhaps easier to learn on, too. You can basically start from a standstill. Short wbs are also handy in town, if you have to stop relatively often.
Longer wheelbases can achieve higher speeds, but may require a higher start speed to get going with pumping.
Just about any topmount deck can used, so if you want to experiment on a budget, you can take a longer deck and drill extra holes for different wheelbases to try.
* As Zach wrote, a Bennett truck up front and a Tracker RTX in the back is a great setup. I use about the same angles as he, and for height you can use a 5 degree wedge and a 6 degree wedge on top of each other. There are tall and low wedges, see which works for you. The height of the wedges helps avoid wheel bite. You need quite long screws to attach the trucks, and the screws may bend a little, but I haven't noticed any of them breaking yet.
With Tracker trucks, I found the neck of the pivot wearing out the pivot cup, so filed the sides of the neck slightly to narrow it a little.
* Loose trucks are a no-no. Loose trucks are not responsive, they're just, well, loose. Experiment with different bushings that are suitable for your weight and wheelbase.
I've enjoyed using ABEC11 Reflex and Venom SHR, or even white Khiros on very short wheelbases since I'm quite skinny. If you like, you can use barrel-shaped ones on both sides, and replace the roadside cupped washer with a large flat one. Experiment with tightness of the kingpin, that and the bushings make a huge difference.
* Large grippy wheels with square lips have worked best for me, Seismic Speed Vents on several setups, and Avila Race Formula on a very short wheelbase setup. But you can try a lot of wheels, I have a short cruiser deck set up for slow-speed in-town pumping that has round-lipped old Cults, haven't had them slip or slide unintentionally.
I've bought Speed Vents also second-hand, and have been happy with them.
* A concave deck can help with foot grip, but some say it tires or hurts their feet on long distances. On flat decks, once you find an ideal spot for your front foot, you can make a stopper by simply attaching a bushing on top to keep your foot in place.
* If you want to, you can face the hangers of your trucks. This means making sure the hanger face is perpendicular to the axle. With cast trucks, the hanger face surface may be uneven or at a bad angle. I haven't noticed huge differences in performance, but folks say it helps with bearing wear and allows the wheels sit more precisely. I've done it just in case, and because I like to tinker with customization.
The metal is usually soft enough that you can do the task manually. Shave the metal very little, just enough so the face is flat. Here are a couple of good pics (not mine):
https://www.peterverdone.com/wiki/index.php?title=Facing_Hangers
That person is using a counterbore, but a similar tool can be found by the names tenon / dowel / plug cutter, and can come without a pilot bit. Shouldn't cost much. Just make sure the center fits your axle exactly.
My technique is largely front-truck centric, it pulls and the tail mainly follows. It's good in town, since it does not require that much space sideways, but I want to learn to utilize the back foot better, especially with longer distances and less crowded routes.