The events are split between English/Falmouth Harbours and Jolly Harbour. Getting dock space at Nelson's Dockyard in English Harbour, where the event is pretty much hosted, is almost impossible (not too many boats fit on the dock and often the 100+ footers use most of the space. You can anchor out in English Harbour (crowded but protected) or in Falmouth (huge, empty and still protected, but a longer dinghy ride - I stayed there for the whole last race week). Jolly Harbour is your only real choice if you really wish dock space, but even then you will certainly have to share/raft up or otherwise do something for the one night where all the race boats spend in Jolly harbour. Jolly is a bit too far to motor/sail comfortably for most events if you plan on participating in the races.
Make sure to get to the firs party early - those Mount Gay hats and T-Shirts are collectors items and run out in the first hours on the first day