I went to a community college 47 miles from my home from 7:00 am to 1:00 pm then worked 8 hours. I had no time to study after class so I had all of my tests passed before the first day of school January 2004. The practice tests were a great help to me and I passed every test the first time. Since the DMV was only a mile from my house I took the tests one at a time but found the practice tests VERY helpful.
The practice tests are pretty close to the real deal. I took my tests on Christmas Eve and passed without any issue. Much of it is common sense, I liked the practice tests as you can get a feel for the wording of the actual questions. They're making it pretty hard to fail in NY, Not sure about other states but all were 3-option multiple choice. That said I saw a kid fail his regular non-CDL permit test while I was there. I mean, how do you do that.