KenKen Puzzles can be found on the Internet under many different names, usually to avoid copyright infringement on the KenKen name. The following list is found on the official Calcudoku Website:
Calcudoku, Newdoku, Rekendoku, MathDoku, Kashikoku-Naru,
KenKen, Kendoku, Sumdoku, Calkuro, K-Doku, Keen, NekNek, CanCan, Square
Wisdom, Emono,
Minuplu, LatinCalc, Yukendo, ArithmeGrid, Hitoshii, Inky, SquareLogic,
TomTom
Many sites provide an option for solving their puzzles online as well as printing out puzzles to solve:
Caludoku provides an excellent page on basic and advanced solving techniques:
Calcudoku also provides an interesting online forum for players to discuss problems and exchange information: