Please forgive me, but I'm gonna throw a small monkey wrench into your machine here.
#1: Your routine puts back and chest in the same workout. For my money that's too much muscle to try to work effectively in one workout.
#2: Legs are arguably the most difficult body part to work COMPLETELY. A good leg day is a stone cold biatch. If you do it right, you'll barely be able to walk out of the gym. For that reason, I work legs the first day of the week, after I've had a full weekend to recover from the previous week's workouts.
So, with those thoughts in mind, I'd suggest more of a power routine which stresses the three major muscle groups.
Monday: Legs - Squats, squats and more squats
Wednesday: Chest - Bench presses (Either straight bar or dumbells)
Thursday: Back - Deadlifts and bent over barbell rows
These very simple exercise, if done to muscular failure will work your entire body very effectively and add that muscle you're looking for. If you feel you really HAVE to work your arms, do triceps on chest day and biceps on back day. They're already warmed and worked pretty effectively from the basic exercies I've listed. Just do two or three sets of isolation exercies at the end of your workout. As far as getting lean is concerned, that's not going to happen in the gym, that will happen at the dinner table. Your body fat % is determined by your diet, not your exercise routine.
