I really urge you to post this in the exercise forum section
http://www.3fatchicks.com/forum/forumdisplay.php?f=34
I can only tell you what I do. I go six days a week. My trainers (I have two gyms, one at work and one near home) both recommend one rest day. Mine is usually a Saturday.
I do weights/toning one day and then cardio the next (naturally there is cardio on weight day too to warm up and to keep the heart rate up) I tend to do whole body weights, as when I did one day legs, one day arms etc it didn't work for me, I was gaining inches in one area and losing in another. You need to change up your routine every 6 weeks with weight training, or you will seriously plateau and get discouraged (ask me how I know)
I'm no trainer, but I think at your weight (and it is the same as mine give or take) you would benefit from upping your cardio. Muscle is great, but cardio is what burns the fat. Also bear in mind that the cardio machines calorie burn is rarely accurate and usually overstated, if you don't already, try logging your exercise in Fitday or equivalent.
Hope this helps!