rat poison.
Seriously Dr. OZ, just work with what you've got. You work from home, OK...
1. when do you have a spare 30mins to exercise?
2. now what is the most logical piece of cardio to do in that time?
3. how many days a week can you devote to it?
My advice would be to start with at least 3 days of solid, sweating cardio for 30mins to 1 hour - depending on how long you can devote to it. Just work up a good sweat 3 times a week and then progress to four and then five, etc. If you're predisposed to weightgain, you'll need to sweat/cardio your ass off.
Nutrition, avoid sugars. Eat fruit and veges, protein (save the animals, keep it nuts, egg, soy, etc) and decent carbs but nothing too fatty or too many carbs. Just have small, healthy meals 3-4 times a day and snack a little bit inbetween on things like veges or fruits. Good luck.