U.S. med students take it after our 2nd year, right before starting clinical clerkships. In other words, we're under some fairly significant time pressure. Most schools give anywhere from 1 month to 6-7 weeks of summer vacation after year 2. As such, you might come across study schedules that are 30 days long with 8 hours of study each days. That kind of schedule, or some variation of it, is pretty typical for the "average" U.S. med student, so it probably won't apply to an internation student.
You definitely want "First Aid for the USMLE Step 1" as your starting point like theodore mentioned. It's very highly regarded. There's an advice section in there for international students.