Dude! Even more motivation to keep this joirney going (your wife and son). I have a 3 year old son and a little girl on the way in April, and that is my biggest motivation each time I need to push out that extra rep. or do that last 10 minutes of boring ass cardio!
If you're trying to lose weight, try to concentrate more on higher reps (12-15). If you go too heavy, too quick, you're going to start hurting things. Just friendly advice.
Also, get yourself a workout journal, so you can track your weight, reps, sets, and even how you're feeling each day. I know it sounds corny, but it's helped me figure out what works and what doesn't as well as, what I should be eating before a workout (If I'm getting light headed or have enough energy to get through a workout). When you start cutting calories and such, you need to make sure you know what works. I made my own, but the east button is a Fitbook. http://www.getfitbook.com/fitbook-p/ftbk-black-red-001.htm
Again, just my .02 of knowing what works and what doesn't for me YMMV