If you go for a 3 day split, personally for growth and strength, i'd focus your three workouts round the 3 main compound movements - Squats, Deadlifts and Benchpress.
This is a post i did for someone else on here a while ago, but it can go for you too;
Ideal 3 day split would be;
Chest/Bi's
Back/Tri's
Legs/Shoulders
Just focus around the 3 big lifts would be my main advice. All the other excercises should fit in around them. Start every workout with the heavy compound. If you like knowing how strong you are, chuck a 1 rep maximum lift in each session, this wont do any harm.
Chest
Flat Bench - this is the heavy compound
Incline DB Press
Flat DB Flies
Cable Crossovers
Legs
Squats - this is the heavy compound
Calve Raises
BB Lunges
Leg Raises
Back
Deadlift - heavy compound
Yates/Bent Over BB Rows
Lat Pulldown
T Bar Row
Shoulders
Standing Barbell Shoulder Press - heavy compound
Side DB raises
Front DB raises
Shrugs (i do these on shoulder day, some do it on back)
Biceps
Straight Bar Curls - heavy compound
Seated DB Curls
Cable Curls
Triceps
Close Grip Bench Press - heavy compound
Cable Pushdowns, Straight Bar
Overhead DB extension
On the compound movements, go as heavy as you can, for 4 sets of 6-8 reps. This will build strength and size(have you ever seen a small powerlifter?) the rest of the movements should be seen as assistance work almost.
All that said, the key to building and maintaining muscle is diet. You will see "n00b" gains for the first 6/8weeks with any kind of weight training, after that without proper(or at least average) nutrition not much will change.
All the above is my opinion/experience. Everyone differs though. You might find behind the neck shoulder pressing works for you for example, if so - do it.
P.S. Once i'm back training in 3/4 weeks me, you and paul can get a session or two in, he needs it more than us though! haha!
Good to see your still sticking at it too.