Hey Hally,
For the most part, american grads won't be the best resource for this considering our motto is 2 months for step 1, 2 weeks for step 2 and a number 2 pencil for step 3. Basically, most grads here don't study beyond 4 weeks and very rarely beyond 8 weeks (never heard of an american grad beyond this).
How long it takes you to study depends on how departed you are from clinical work, your base of clinical and basic medical knowledge, test taking and english skills and what your goal is in terms of score (e.g., are you trying to match into PM and R or Ortho, etc...).