I'm learning to play Dominoes from http://www.pogo.com.   I practice against the computer mostly until someone else joins.  I'm still learning the basics and strategies  It's neat the way the playable tiles highlight for you, the placement is outlined on the bone yard and the end tiles are totaled for you or I would have been lost. (I had to quit looking at end total displayed and learn to figure the ends myself)  It helps me learn because sometimes I won and wondered why.  I'm hoping to get good enough to play with my friends.