Thought I'd add my 2 cents to this thread. First of all, if you really want to get in shape, not just for today or next month, you must do something that you like. This means you will be more likely to continue the activity (because you like it) and hopefully make it a part of your everyday lifestyle. You may mix it up and include some activities that you would not normally do or like (push ups until you drop, or run the mile in 8:00), but there must be some exercise that you consistently take part in that you can call your own, a favorite if you will, and make a part of your life. Your body will let you know if you are being too hard on it and your mind will let you know if you are not putting in the effort. If you need further direction feel free to contact me. If your interested in my training background, I'd be glad to tell ya about it.
Idabow