A good routine at the gym can make all the difference in results. Before starting any system or plan or regime, you should get clearance from your doctor. Some people have done these routines and have gotten pretty decent results.
If you are just beginning lifting weights than you probably should do one muscle a day unless you are real sore the next, than you just go ever other day. Example: Mon is chest, Tues is shoulders, Wed is biceps and triceps, Thru is legs and Friday is back. Do this for about 12 weeks and than move on too this routine.
For example: Mon is chest and biceps, Tues is shoulders and triceps, Wed is legs and Fri is back day. Again if you are real sore than go to the gym every other day. As for your abs, you can probably work them out whenever you go to the gym and do some cardio as well, because you don’t want too build a big muscle body and get too big and maybe get a bad heart.
For abs also, sit ups are the most common exercise to do your abs or if you find it hard too do abs at the gym, than buy an abs machine from a retail store. Again, you should always get clearance from your doctor or a professional before you start any program or diet.