I've tried lifting weights according to what programs tell you to do(do this exercise that works one muscle and doesn't get your heart rate up very much, 3 sets) and I think it's a bad way to do things. My muscles would get so sore and take so long to heal. I would feel like doing nothing. No ambition to do anything while I was healing. I was really hungry too so I ate and I gained some fat. My body craved protein, which it needed, but extra carbs and fat it didn't need. So I said to myself, "This can't be good for you."
So last Monday I started doing Calisthenics. I did Jumping Jacks, Pushups, Pullups, Climbers, and Squats all 1 set. It took me about 15 mins. I was sore the next day, but it wasn't bad. Wednesday I wasn't sore so I did another set that morning. Felt good the rest of the day and was a little sore the next day. Friday I wasn't sore so I did 2 sets that day and I'm a little sore today. My muscles feel stronger and look bigger. I have energy and feel good.
I think starting out slow is a good thing. I do cycling and you start out slow when you first start out. If you don't you will bonk and feel like crap for a few days. Same thing can apply to weight lifting. These programs try and get you to do too much too fast and all it does it put you behind and make you feel like crap.
Calisthenics work all the muscle groups. Muscles are made to work in groups. Does working out just your bicep make it easier to lift things compared to doing just pullups. I don't think so.
Getting your heart rate up is good for muscle building. Blood feeds the muscle and if you get your heart rate up more then more blood is flowing to the muscles to feed them. I believe this makes them less sore and heals them faster from the workout.
It's about what you can do. I don't have a high income. I can't afford P90x or Insanity. I got all the information I needed to try P90x from the worksheets they provide free online. Calisthenics don't cost any money, except maybe a pullup apperatis. I can't do many real pushups so I do it on my knees. You can even do them on a wall. I can't do pullups in the air. I do them with my heals on the ground and somewhat assisted by my legs. I also don't go to muscle failure. Working your muscle till it's dead means that muscle will be really tired for the rest of day and you won't feel like using it.
So give Calisthenics a try.