A small tip for people who are doing split bodypart days, try having 2 days (one at beginning of week, and one at the end) for legs if you feel you're lacking there. When your lower body gets worked on correctly, your upper body will follow, especially if you do ATG squats (ass to grass). Remember, legs have separate push and pull (front and back) parts, too!
Also, DO NOT CURL IN THE SQUAT RACK. ;)
Anyway, I plan on getting into working out again as soon as this little nick in my upper left back goes away. My plan is a 3 day a week compound exercise routine. It's actually Mark Rippetoe's starting strength program of which I've had damn good results before in the past (also good for people just getting back into working out after a long period). It has 2 workouts that you alternate.
Week 1: A, B, A
Week 2: B, A, B
Repeat
Workout A:
ATG Squats 3x5
Flat Bench Press 3x5
Deadlift 1x5
Workout B:
ATG Squats 3x5
Standing Overhead Press 3x5
Powerclean 3x3
The primary goal of this workout is to add weight to the bar as quickly as possible, but seeing as I'm a fair bit older than the last time I've worked out, I'm gonna take it a little easy on that. I plan on doing this routine until my strength gains start having some noticeable diminishing returns, and then I'm gonna go for Bill Starr's 5x5 workout.
http://startingstrength.wikia.com/wiki/Bill_Starr_5x5
As far as diet goes, I've always had a problem with a strict diet plan. It hasn't hindered me at all, but, again, seeing as I'm a little older I think it'd be a good idea to have somewhat of a diet plan.
Edit: This image bothers the hell out of me and I need to address it.
1. Fats are actually 9 calories per gram and do not directly correlate to gaining fat! Fat is gained from calories not burned, period! (barring genetics). Best sources of fat come from nut oils and olive oil. (This was the start of the overall discreditation of the picture...)
2. The general rule of thumb for protein is actually 1 gram per lb of body weight.
3. Fish supplements are a great source of omega 3's and healthy fats, it only indirectly helps you to get better workout results, but all in all, they're a great overall health resource for your heart, that's about it!
4. I know yogurt is healthy, but, seriously?
5. Cayenne pepper? WTF?
6. I'd love to see the study of green tea helping to reduce fat absorption by 33%... If that's true, I'd be drinking only that for the rest of my life.
A couple of other things to mention: Everyone has a six pack, if you want yours to be visible, then yes, you gotta exercise while you're on a calorie deficit (cutting) diet. Don't discredit certain lower body workouts (particularly squats and deadlifts) for working out your core. They workout your core isometrically, rather than actively though, but only if you don't use assistance such as the belt thing.