I second the home workout idea.
1) It's way easier to motivate yourself to put a DVD in than organise to get all your gear together and head to a gym.
2) There's no way I could go to a gym pre-Top surgery. Even though a part of me truly despises it, I work out in a sports bra...and then basketball shorts (or just boxers if it's a really hot day) as a way to kinda balance it lol. I find if you want to get the best workout a binder isn't good. It limits range of motion and it limits how far I can push myself because I get too warm and sweaty way too fast. I know this as fact because I have to wear one when I go to Taekwon-do and I get tired much faster there and sweat so hard my belt gets soaked. When I finally came out there and showed my instructor what my binder was like it was like a light bulb moment for him in why I tend to leave a puddle of sweat during cool down exercises lol. In public I couldn't go anywhere without a binder. If I went to a gym, I'd end up having a crappy workout because I'd be so limited. Some can use a compression shirt, which can be good for more strength training exercises but I still don't recommend compression for cardio because the sweat factor overrules. Some may think more sweat = good and that's true. The more you sweat the better the workout. However, I'd rather reach the same level of sweat after working out for a solid, hard 1 hour session than working out for 30 mins and finding myself either unable to keep going or half assing it the last 30 mins.
3) If you're having a crappy day and don't have a lot of energy, you can do as much as you can and then either stop or take extra breaks. In a gym there's almost that extra drive that if you're not ready to hit the gym hard, you don't go because you don't want to look like the pathetic wus at the gym.
4) If you're not fit or you don't have a lot of muscle, it can be quite off putting to go to a gym and be around people who are fit and look much better than you. It's easy to find a gym environment intimidating.
5) You go at your own pace and stay at your comfort level. When surrounded by others and worrying about looking like a weakling there's a potential to push yourself too hard, in a bad way. To try too high a weight, or to run longer because when you got on the treadmill the guy next to you had already been running for a while and he's still going so you need to keep going, and other such nonsense our silly little brains come up with. At home, there's no one to impress or look pathetic in front of. It's you and a TV screen, that's it!
6) There's lots of workouts you can do from home that require no or minimal workout equipment. Programs from Beachbody (what I also use, I've completed Insanity and working through P90X) have a wide range of programs for different ability levels. And even programs like Insanity incorporate both cardio and strength training without one piece of equipment. WARNING: I don't advise anyone do this particular program off the bat, work up to something like that, it's truly mental! It's just a good example of a program without any equipment that still incorporates strength training and gets good results. Other programs might only need something like wrist or ankle weights, which are often supplied with the program. There's other programs, like P90X that do require things like weights but they're advanced and shouldn't even be something anyone non athletic should be looking into. You don't have to go with Beachbody (I make no money off them) it's just that I personally find the programs great as long as you go with something aimed at your ability level. I did some hip hop abs with a friend not too long back and that was a TON of fun! Lol.
And you know what, if none of that sounds good, there's loads of places you can get exercise. Dancing is exercising - all forms. Ballroom to street. Cycling. Rock climbing. Roller blading. Skateboarding. And my favourite - martial arts! Everyone should do martial arts, it's exercise, fun and an AMAZING stress reliever. Just picture whatever or whoever is bugging you on a pad and take out your frustration

.
If you're looking into building your upper body, pushups are awesome. There's this whole 100 pushups thing I've seen going around, at least on my Facebook. If you want to do that you can but instead I would far more recommend varying the type of pushups than just sticking to one type of pushup. You want to work the whole upper body, so one type of pushup isn't as good.
I tend to do most of the following vid pushups in one long session taking 60 sec breaks in between each set. Watch the video properly, not every pushup has elbows going out to side, sometimes elbows go back and this works the triceps. Quality over quantity and keep your back flat! Concentrating on tucking your hips in and engaging the abs. DO NOT be tempted to use your back or even stomach for any pushups, just keep the back flat and the abs tight - and ALWAYS check you're tucking your hips in to have the correct posture. The work should be all in the arms, shoulders and chest, or you stop! This means it shouldn't affect scoliosis, in fact, pushups are advised for people with scoliosis as it actually strengthen the back muscle stabilisers (that stabilise the spine). From this video though I would advise staying with the simple to start and move up slowly, and maybe taking out ones where you're having to move your body through a range of motion, like hindu pushups. Vertical press would be fine though because you should be engaging your shoulders, not back at all, and if you find you are - STOP! This one is great for working on a V shape too.