I don't know about creatine, but as far as cardio goes...
I've read that walking burns as much energy as running, so I would recomend walking. Not easy downhill walking, of course. If you can, get a treadmill. I got a $400 treadmill, and while there are some features I would like it to have, it does great for me. I love it.
The object in cardio is to get your heart rate to 80% of your max. Max is about 220-your age, so 80% would be max multiplied by .8. You can find charts on the `net.
So get your walk to a pace and incline that maintains that heart rate, and you will be doing great. 20-35 minutes a day is good. I've lost 5 lbs since I started walking on my treadmill a couple weeks ago, without any other real change in diet or anything else. (The changes in diet etc started today...see my thread Xenedrine).
edited to add: Regarding when to do cardio (before or after lifting), I read that you should do cardio [i]after[/i] lifting. The logic was that lifting will use the muscle glycogen for energy, and when you did your cardio after using up the muscle glycogen, the fat burn starts sooner.
anyway...I hope all this mumbling is helpful.
Good luck!
Scott