Practice here, then obliterate your friends!
Drag and Drop. For a double jump, drag and drop twice. Blue goes first. Also called Draughts.
Note about multiple jumps: it is a basic rule in checkers that if you can jump (capture) then you must. If after that jump your piece can do another jump then it must (called a "double jump"), and if it can do another it must ("triple jump"), and so on!