First you need a short 2 handed plane 8" to 10" in length called a smooth plane.
Second, a 14" long plane or a "jack plane"
Third a 18" to 20" long "jointer" plane for straiughtening long edges for glue ups.
Forth, a low angle block plane for beveling and various mall chores.
Fifth, a scrub plane with a curved blade for dealing with rough sawn or very twisted lumber for taking aggressive cuts:
OR just grind a 3" radius in a spare blade for your short plane, but it's a bit of a hassle changing blades back and forth.
There are others in between, but that's a basic set. There are some really expensive versions by Veritas as you see from the links. I found mine in garage sales, swap meets and ebay. I've owned my Millers Falls 14" plane since I was 16 years old, bought it new at the local hardware store.
In full disclosure, I don't hand plane a lot of my rough sawn boards, having a jointer and thickness planer, but when I need them I gladly use them, especially the block planes... you can't have too many. :smile3:
As far as technique goes, learn to read grain direction and plane "downhill" to avoid tearout. When joining boards for a top, have all the grains going in the same direction or you will not get a tearout free surface when leveling it out. End grain requires a razor sharp blade and a very stable support vise. plane it from each end to avoid tearout OR use a backer. Hold your plane at aslight angle or "skewed" to the grain direction and it will shave with less effort.
Avoid looking into the Japanese style planes, they will astound you with their ability to make paper thin shavings. It will only want you to buy all you can afford, an entirely new basic set AND a whole different way of using them... on the "pull stroke".