It's only a lot of reading if you do it.

Over the last few years, as I told people that I wanted to go to law school I was met with a lot of comments along the lines of, "I sure hope you like to read, because you'll be doing a lot of it." Well, I wouldn't say that I love reading, but I certainly don't dislike it. Given the time and interesting subject matter I definitely like to read. God knows I got sucked into those first two Twilight books (just the first two, they got really ridiculous and annoying after that and I had to just get the summaries of the last two from Wikipedia). Also, I never really acquired the skill of speed reading so I was slightly worried that I'd spend the next three years in a dark corner of the law library reading until my eyes bled.
Thankfully, like most things, it really hasn't been as bad as people said it would be. That's not to say that's it's been a walk through the park. See, those people who told me I'd be doing a lot of reading had it slightly wrong (or perhaps I just mistook their statements). It's not the quantity of reading, it's the quality. I'd say on average I only have to read 40-60 pages a week per class. However, you are expected to know the ins and outs of each case you read for class. You should know who was arguing what and why. What the court meant by what they said. Even, what the court meant by what it didn't say.
However, you will almost certainly NOT be tested on the cases that you've read (though some professors may give extra points if you can name the relevant ones on the exam). The whole point to reading and understanding cases is that they illustrate some part of the law (or in some cases what used to be the law). In law school, you don't have textbooks that teach you the rules, you learn from examples. So, try not to get hung up on and upset over a certain case because the bad man went free or the poor old widow didn't receive any damages for her husband's wrongful death, but ask yourself what is the significant law from this case. And that, dear friends, is quite possibly the most valuable piece of information I got going into law school.

*One minor, semi-related note: buy your books online on Amazon or eBay. It's so much cheaper than the books stores, even brand new!