If you want to start lifting some weights and want to build bigger muscles you need to split different muscle groups into different days.
Here's my workout routine (Just for example)
monday-Chest (30 min Cardio Either on a treadmil or Eliptical)
tuesday-Back/Forearms (30 min cardio)
Wednesday-Legs/Abs (Already worked out legs, if you did it right you'll be walking funny and Cardio isn't happening)
Thursday-Arms (Biceps/Triceps) (30 min cardio)
Friday-Shoulders (30 min cardio)
Saturday-Be Lazy (Wanna do some more cardio, go for it if not meh!)
Sunday- Re-read Saturday
The reason for splitting up muscle groups is so you can focus on that particular muscle group for that day. Why would you want to exercise every muscle in your body all in one workout? (Some people do it, I don't get it, they tell me it's a method of cardio to do several muscle groups quickly.....i'll stick with a treadmill) Anyways! Being able to focus on one to two muscle groups allows you to strictly isolate that muscle and focus on each part of that muscle.
Let's take Chest for example! Your Chest Is split into your pectoralis major and minor, and when you work it out you work out the top part of your chest and the bottom part, however the chest also has the middle section (You often see people on the bench press, to work out the middle of their chest, and then they increase the bench their sitting on to do inclined bench press to work out the top part of your muscle and then they do what is called a decline bench press, where the bench looks like it's at a downward slope, this helps workout the bottom of your chest.
Many of your muscles are split into different sections, and being able to workout each muscle section on the same day allows for a better workout of that muscle group.
To start off you need to do light weight, probably much lighter than you think for the first couple of weeks then start increasing the weight. Cardio is up to you, how much can you do? I do 30 min on a treadmill at it's highest incline at a power walk pace.
There's a lot of things to consider especially your diet. I was talking to a big guy at the Y and he said if you're working out with a poor diet then it's a lot like going up stream in a row boat, you'll get somewhere eventually but in the long run you'll stay where you are. (Eat a lean chicken breast and a half cup of cooked brown rice after your workout) It gives you good lean protein for your body to use and the brown rice will help give you back your energy.
There's a lot to talk about, I could go on for a long time, but I hope this helps.
