Having been in and out of this business a couple of times I have taken both L&H and the 6&63 exams twice. Here is what I have done successfully. Take the cheapest pre-licensing course that I can find that fulfills the requirement (I'm a tightwad). Get a computer based practice exam and take the questions over and over until I can score close to 90. Go take the exam. I have always passed with scored that ranged from the low 80's to the high 90's. The only time I had a problem was on the 63 when I had a bunch of questions that were not covered in the practice exam (crappy practice exam) and I barely passed. I have never studied a book.
I used a blend of this and the book. I immediately started taking the tests to see what I knew and didn't know. Get the answer, and if it was logical then I remembered it. If I didn't have a clue as to why then I went back to read in the book until I understood. I took the L&H twice, passed both (license lapsed for a couple years) and passed the P&C on first try as well. Was much faster and more effective learning for me than reading the book cover to cover. Remember the test tries to confuse you more than question your knowledge so go slow and read the questions carefully.