Thanks! I appreciate it. I would start with walking or swimming, being that it is summer. And only do what you can. If 5-10 minutes is all you can do, then so be it. Increase every week or so just one minute.
Always, always remember to stretch. It helps to prevent injury and some soreness. Which is another reason why you should take it easy at first. You don't wanna get so sore to the point where you skip 3 or 4 days just because you're in pain. You have ease back into an exercise routine.
If you want to strength train and tone, start with a weight that you can do 10-12 reps, 3 sets. So if you're comfortable lifting 10lbs without horrible struggle, lift 3 sets 10 times each. I personally only do 15 lbs. and I won't go past that because by the time you get to the 3rd set, you'll definitely feel the burn. And that's all you're looking for.
I would check with your physician or dietician to get a good idea of how much you're allowed to workout for. If you work out too much, you go into starvation mode and won't lose any weight. Big no no!
Best of luck to you! =)
And remember, as bad as it is at the beginning, it gets easier and you'll feel amazing at the end.