I have not worked out like I used to since about a year ago. I used to workout 5 days a week training different muscle groups each time. I was wondering now that I am about to start up again should I jump right into the old workouts and go full blast or should I try to build up to what I was doing a year ago?????????
Slow and steady....and thats all im gonna say...
Jumping right in would be a great way to injure or overtrain yourself.
Start with easy full body workout 3x a week, with highish reps (10-12) for a few sets and far away from failure. If you didn't squat or deadlift before, now is a good time to start.
Then, check out the articles on this site (esp. Waterbury's) and pick a good routine. ABBH (Anti BB Hypertrophy program) or TBT (Total Body Training) are something that worked for many people.