Depending on what you can physically handle, I would suggest doing cardio of some form 4-5 days per week and starting some strength training 3 days per week. Try to go for more than 30 mins cardio (I personally aim for 45 mins to 1 hour).
For the strength training, you could get some resistance bands, free weights and a stability ball and have a look for a good DVD so you can do it at home. Otherwise, pick up a fitness magazine and flick through for some ideas. If you are completely foreign to strength training, pehaps post a message in the ladies who lift section and they will be able to give you some more specific details. I have never used it, but Body For Life for Women is a popular program on here for strength training.
Remember, any movement is better than none