I came straight out of undergrad. If by relating to jobs you've had, you can get by by doing the 8-5 approach. However, there are times that I wouldn't recommend it. I'd say there are some days when you can do only a couple of hours of reading and be prepared for class the next day, and there are other days when there just don't seem to be enough hours in the day to even get done. I don't think there's a formula. You just have to go with what your personality requires.
Reading cases and such is what you'll do in law school. I guess it's in the right direction, but it is very inefficient. The way law school goes is like any class in undergrad. There is a unit. That unit has subunits. The cases you read will apply whatever law you're learning about to real facts. However, the difficulty is that you don't know which subjects each individual professor will cover in a particular semester. Honestly, I don't think preparing for classes like Contracts, Property, Civ Pro, Torts, etc. will help. Your professors will beat those subjects to do death anyway.
If it makes people feel any better, law school isn't hard, it's just a lot of work. Conceptually, most of the time law school seems logical. To do well, just put in the time once you've started.