I'm generally in the gym 4 - 5 times a week. If I'm pressed for time, I make sure I crank out 3 - 4 sets of half squats (full ones screw with your knees and make your butt square), and I have my own technique, combining weight bearing with basic ballet, doing stretches in between sets.
Then I make sure I get in 4 - 6 sets of bench presses, flat and incline, close and regular grip.
As long as I get those basics in, I can keep up dumping fat, slowly but surely, and I make sure I get all my core muscles involved in the squats.
The dogs normally take me for about 3 - 5 miles of walk most days as well.
The exercise ball is great for the core muscles, and Becca, I'd recommend one to you, especially.