Circuit training is a method of exercise with which you will get the combination of the benefits of weight lifting along with cardio. Since you may be unfamiliar with the way that circuit training works, here are some helpful tips to get you started. Along with some of the exercises, I'll provide you with some hints you can use at home. Though most gyms have circuit training classes, you'll have enough information to start a training program at home.
Circuit training takes its name from an electrical circuit in that you go all the way around a series of exercises until you "complete the circuit" before beginning the sequence again. For example, you might do an upper body exercise like pull ups, followed by a lower body exercise like squats, followed by a full body exercise like jumping jacks. Since your heart rate remains at a relatively high rate during the entire circuit, you will get a high quality workout that will give you results faster. You get the advantages of strength training and the benefits of cardio at the same time.
When I first started circuit training I found out that it was best to use between 5-10 exercises in each circuit. You want a total of 20-25 sets so if you choose 5 exercises, you are going to have to do at least 4 rounds whereas if you have 8 exercises you only have to complete 3 rounds. Make sure to warm up by moving your arms and legs rather than using static stretching. Do that afterwards. You want to do a dynamic (moving) warm up to get blood into the muscles.
All right, now that we are done with our warm up, let's start our circuit. A good whole body exercise like jumping jacks is a good way to start. Next we need some good upper body exercises. Lets use two types of push ups. I like to use Hindu push ups and spiderman push ups but since we are designing this for beginners, we'll use the standard push up which you can even do on your knees, and close grip push ups, with the hands close together. Let's throw in an inverted row to round out the upper body exercises.
Now we need some lower body exercises. Lets use lunges, mountain climbers, step ups, and squats. Now all we have left is to arrange them. We'll put the jumping jacks at the beginning to get the whole body ready for action. Next we'll arrange the exercises alternating upper and lower body exercises. We call this non-opposing exercises. The upper body exercise does not share any muscle groups with the previous or subsequent lower body exercises. Now all we have to do is order the exercises and we come up with this:
Jumping Jacks 60
Push Ups 20
Mountain Climbers 20/leg
Step Ups 20
Inverted Rows 20
Close Grip Push Ups 20
(Repeat 3 times)
Now you know what you need to get to started. As you get stronger you can add more repetitions and modify the exercises to incorporate more difficult exercise variations.