jackostein, bowyer road end is good because it has good access but spacemonky is right it gets crowded real quick.
(just joking about 20 of us comming down there spacemonkey)

Largs bay sailing club is a good area. SW Straight up the beach flat water and shallow for beginners.
Henley is deaper water and waves.
Depends on what you are doing really henley and bowyer road seem to have the most people at them.