Step 2: Get to know your pentominoes
There are twelve unique shapes in pentominoes all made out of five cubes each. Based on the shapes, they are all named after letters. Most of very obvious, that is the "L" shaped piece is called the "L." Other pieces need a bit of an imagination. The shapes/letters are
F, I, L, N, P, T, U, V, W, X, Y, Z.
The way to remember the letters is the nonsense word, "filnop" and the end of the alphabet, T through Z.
Here are the first five shapes/letters: