It all depends on what you want to accomplish with your lifting. Either way, the *vast* majority of people lift too damned much and it slows down their progress. Why?
Well, you're right in having to break down the muscle fibers. But then what? They need to repair themselves. And they repair themselves at a much slower rate than they break down. You *need* to rest your muscles if you want them to develop.
I'm into overall fitness and without knowing your specific goals, I'll just tell you what I do.
Mon--lower body lifting. Calves, quads, glutes, hammys, and abs.
Teus--cardio. Usually intervals for fat burning, then something fun, usually mountainbiking or running.
Wed--upper body lifting. Bis, Tris, shoulders, lats, lower back, pecs, etc.
Thurs--cardio. See above.
Fri--lower body lifting. See above.
Sunday--lounge around and eat pizza and drink beer and scratch my ass so I don't burn out.
Then on monday I start off with upper body lifting to continue the cycle.
Varry your lifts. For instance, for biceps, do standard dumbbell curls (locked wrist, full range of motion from straight arm to full curl, squeeze at the top of the rep) one week, then do half dumbbell curls (starting at full extention, hold the bar with your fingers, with fingers and wrist relaxed. Lead up with your wrist and stop when your arm is at a 90 degree angle, squeeze at the top of the rep)
This works wonders with the right nutrition. You need a balance. Low fat (NOT no fat--you need fats for hair, skin, etc.), roughly equal ammounts of *quality* protein and *quality* carbs. Too much of one and not enough of another will hurt you. Eat smaller, more frequent meals over large, spread out meals. I usually eat 6-8 times a day.
--edit-- This is based on Bill Phillips' book Body for Life
which is worth every penny. Sorry for forgetting to credit.