Thanks! I've done some yoga in the past, and it can be quite tricky to do, but apart from the breathing and stretching it did I was never quite sure whether it was as good for me as, say, a run/cycle.
Since I don't have access to a gym with weights and only a small set of dumbbells I'm not sure how much of the weight training side of this I can do, but I might try the running thing and perhaps some simpler weights that I can do with dumbbells. Maybe pick up a yoga class again too :)
Plyometrics are an excellent substitute if you can't get to weights. These are basically calisthenics with explosive movements. For instance, squats where you explode upward into a jump and try to bring your knees to your chest, or push-ups where you explode upward and clap before catching yourself build strength (and stress the bone, which seems to be beneficial in preventing osteoporosis). Also, adding sprints to the end of your run is beneficial (I really like interval training in general, actually).
In an earlier post of mine, I made reference to the Cosgrove Evil 8. If you're looking for something that you can do inside, these would be great for a beginner to do with a broomstick. It would give you an opportunity to learn a majority of the most important (and basic) compound lifts without being intimidated by a gym atmosphere. It would also give you one hell of a workout in a relatively short amount of time, something great for doing at home.
Being able to perform each of these lifts properly would make you more knowledgeable than MOST people at your average ballys or 24 hour fitness, and that should give you plenty of confidence to start busting your ass at the gym.
Since I don't have access to a gym with weights and only a small set of dumbbells I'm not sure how much of the weight training side of this I can do, but I might try the running thing and perhaps some simpler weights that I can do with dumbbells. Maybe pick up a yoga class again too :)