You board a boat at Pier 41 for the short ride across to the island itself. When you disembark, a tour guide greets you and explains the routes to take and what to expect, etc. There is quite a lot of walking up stairs and hills, so for those with disabilities and the like, there is a trolley bus to take you to the top.
We started off by going into the "theatre" to watch a film about the history of the Rock which was very interesting. It outlined the various uses the place has had over the years -- by the Army and, of course, the prison to the Indian occupation in the late 1960s -- and how the place has been turned into the tourist attraction it now is.
Your ticket includes a self-guided tour with a tape recorder and headphones. The tape is extremely impressive, with superb stereo sound that makes you feel like you are experiencing all the things you hear on the tape.
You are told of the conditions the prisoners were kept in and hear the echoes of the doors banging shut and the screaming of the inmates etc. You are told to go to different cells and hear stories of how the marks on the door relate to a failed escape attempt or that Al Capone was thought to have been in this particular cell, etc. The voices change on the tape to people who actually experienced Alcatraz, either as a prison guard or an actual prisoner. There are stories of riots and escapes, and you see cell mock-ups of how some of the prisoners tried to escape by digging out of the back of their cells and leaving hand-made heads in the beds to fools the guards. You'll also learn that Robert Stroud was famous as being the Birdman of Alcatraz but never kept birds on the island -- he earned his nickname as a result of keeping canaries at his previous prison, Leavenworth. Al Capone was also kept here, but no one seems to know exactly in which cell.
Apparently the inmates were given good food in order to keep them from rioting, and given hot rather than cold showers to stop them from becoming acclimatised to cold water in case they were tempted to take a swim. There were a few attempts at escape, none of which were said to be successful, although three men are unaccounted for during the escape depicted in the film The Great Escape. There was no evidence of their survival but, no bodies were found either!
When the tour ends you are free to wander the island. Boats leave every half an hour so you can stay for as long as you want. The tour itself takes about one hour, so you really need to allow yourself a minimum of two, so that you can wander at leisure and visit the shops, etc.