This is how my abs looked from cardio and crunches to post baby to Strength Training with no direct ab work.

January 2011 Cardio only

January 2012 Before I started

November 2012
As far as the lifts that I did, I stuck with compound lifts, which are exercises that make multiple joints move. Examples of compound lifts are Deadlifts, Squats, Bench Press, Rows, and Shoulder Press.
The Squat was the first compound lift that Rob started me with. Squats work muscles in the legs, back and core. We started with body weight squats to work on form but it felt really awkward. I started with the 45lb barbell and increased 10lbs each workout. Form is key. It was easier to learn and work on form with a descent weight.
I looked on YouTube, and this was the best form video I found.
For all my lifts, I do warm up sets to work up to my working weight. Your working weight is your goal weight that you want to lift that day. With squats, I started out by doing just the olympic bar (45lbs) for 5 reps then add weight and do a couple other sets before my working weight. For my working weight I would do 3 sets of 5. For example; if I did 85 for my last working weight and I wanted my working weight to be 95, you could do your warm up of 45lbs for 5 reps, then 65lbs 5 times, then 85 lbs 5 times, then do your working weight of 95lbs 5 times for 3 sets. Squats is one of the hardest lifts for me. It felt very awkward and I got very frustrated with them. I'd improve and get better, then I'd get stuck at a weight. When I was stuck on a weight I would add more sets so that it would stress the muscles enough to still improve. After doing that for awhile I would finally be able to add more weight. I was stuck at squatting 115lbs for a long time. Now I'm squatting 135lbs for my working weight. The most I've done is 155lbs once. Sadly, I don't get to the gym as much as I'd like so I don't get to Squat as much as I want, but I'm hoping to start improving with them again. My next post I'll be talking about my favorite lift, Deadlifts.