The 7 Day Work Out Plan that I put together I have tried and I really like it. It's a simple work out, but it's great! I definitely work up a sweat. You can absolutely modify it to work for you. I personally like the treadmill for walking/jogging, but I know some people (my mom) love the bike. Sometimes I mix up the cardio machines for my 30 minutes of cardio. When it comes to the Leg and Arm exercises make sure to do what works best for you. Maybe 20 reps is too much to start off with. I like to break them down in sets and will likely do 2 sets of 10. For the '20 Cross Punch with Weights' I need to start off with 3lb weights and build up. You might be able to start with heavier weights.
It's all about YOU and where you feel comfortable. Give it a shot and let me know what you think!
Have a happy work out!