I work from home and I TOTALLY RELY on Freedom! When I have work that I really don't want to do, I set it for 20 minutes (the minimum) and it helps me get going. Then I don't need it as much after that.
But if you are trying to get reading done that's not on the computer, you should be aware of something: if your computer goes to sleep, that time doesn't count on the timer. In other words, say you have 10 minutes left on the timer and your computer goes to sleep for an hour. When it wakes up, there will still be 10 minutes left on the timer. That has really messed me up before. I'm on a macbook, it might be different on a PC or a computer that doesn't go to sleep.
I do wish I could set time limits per site per day (and this site would be on the list!).