Originally Posted by skier

If you have an hour or two before bedtime to spare after your workout, I think it should be fine. I don't really know much about how exercise affects sleeping though, I can only speak from my experience.

My suggestion would be to start small. You really don't need very much exercise at all to get fit, and launching yourself at the equipment will just burn ya out and discourage you. Once you've brought the gym into your life's routine, you can then escalate your workout if you want.