wow, congrats on the great weight loss!!!
good tips here. I started on the treadmill then did elliptical and bike. I had to start off slow since I was pretty out of shape in the beginning, couldn't do more than 10 min on the elliptical. I've switched the machines and amount of time lots of times.
someone posted this link a while back people might be interested in about exercise for an overweight beginner
http://www.stumptuous.com/no-fat-chicks
I remember Bob on the Biggest Loser saying he thought it was better to have more of a challenge than to go faster, so I've increased the incline on the treadmill rather than upped the pace particularly (once I got to a pace I felt worked for me). I check my heart rate after about 10 min, that's how I decide on intensity (130 to 140 for my age, 45). Don't be afraid to ask the trainers questions.
for resistance and weights, I think it's a great idea to have a session with a trainer since form and the amounts of weights you use makes a big difference.
I always bring my ipod shuffle, love that thing.