http://www.surf-wax.co.uk/locations/spain/tarifa.htm
this might help.
a guy i was with last year went down there last to check the place out. he was just flying on the beach(no board) but he said he got sandblasted because of the high winds.
not sure it is the best place for beginers to learn to kitesurf, but having never been there before i'm no expert on the place.(the kitesurfing section might be more helpful) If it is too windy in tarifa then just pop into gibralter and play witht he rock monkeys they always seem to keep me amussed for a coupe of hours.
phil.