I'd enjoy it if the rules with some graphics are displayed near the game, for newbies.

e.g. show a word with some green letters and that they have to be in the same spot in the other word. e.g. FUBAR with green B -> __B__

FUBAR with yellow R -> RRRR_ (with gray background and white R to signify "has to be placed somewhere here")

And for the gray letters, I guess.. show them next to the _____ in a trash can?