I am on a rest week this week. I have been going hard for about 13 weeks which some might say is too much. And from a professional standpoint I would have to agree with that. However, during those 12 weeks I made consistent progress even last week (which was supposed to be a rest week) when I hit a few PR's. You have to listen to your body and though for most people, 6-8 weeks is long enough to at least take a back-off week from heavy weights. You need to rest. You're going to get stuck in a rut trying to grind through for 52 straight weeks and you won't make progress.
If you feel like you've stalled in your training, think back to the last time you took some time off, and how good you felt when you finally got to hit the training hard again. Take a week off, set up a new program that is going to help you achieve your goals.
Hit it hard.