K.H.
I would suggest going with him to Lifetime Fitness and just starting out walking around the track or doing a bicycle or possibly even trying swimming a few laps each time you go - until you get comfortable with the gym thing. I know when you walk into those places it's all just so overwhelming and everyone seems to know what to do with each machine and exactly what they need to be doing and how long...it makes you feel, well, pretty stupid sometimes!!
I would start out a little at a time and take it easy - it will take some time to lose the weight and get to feeling better. The thing i notice is that swimming laps or doing exercises in the pool is much more of a work out than most people think, and you can do them on your own. I also like the balance ball work outs - it really works your core muscles and begins toning your whole body. That's something you can do at home with a good balance ball DVD and while you're doing it you feel like you're not getting anything good out of it but when you wake up the next morning you feel it in places you didn't even know you had muscles!
I'm no expert but i do know what has worked for me in the past!! Doing this along with cutting down on sugary drinks and sticking to water (that's hard for me!) along with eating more sensibly is a good thing to do as well. It's so hard to just stop what we've been doing all the years before and cut out cold turkey those things that we love to eat and drink, AND get into an exercise routine. I suggest you pace yourself and, heck, if you have a craving for something chocolate or sweet or even potato chips, just have a couple of bites to ease that craving and drink a huge glass of water! :-)
Good luck!