For reference: the book 5/3/1 can be bought for about 20$ here: http://flexcart.com/members/elitefts...&m=PD&pid=2976
As Derek said, the program is based around "1 month" (if you do 3 days per week your
"month" is actually 5 weeks). It's built for long term progress in strength, but the flexibility of the program (since only the 4 primary lifts are emphasized) allows you to periodize your training without ever really leaving the program.
For instance you could do:
4 months of 5/3/1 focusing on hypertrophy.
4 months of 5/3/1 focusing on max strength (potentially even replacing AMRAP with 2-3 heavy singles after top set).
4 months of 5/3/1 focusing on conditioning.