I do agree with Hookedonpole, because I've also found that thinner does not equal stronger; I've known a lot of ladies that look large, but are as strong as an ox and could probably kick my butt on the pole!
However, I've found that basic exercises really work for me: lifting weights, crunches, push ups, and planks. Veena's strength training on this website are a great resource. I highly recommend trying NOT to get stuck with lifting weights, actually, unless you really find nothing else works for you! They only target one part of your body, and for me, that's very necessary (I've got some big muscles on some parts, and some really wimpy ones in others, so the targeting really makes me balance out). However, doing something that speaks to many areas of the body, and keeps your core engaged, will probably show faster results and better overall co-ordination!
As for weight loss... well, the best I can say is keep at what you're doing, and what you're looking to do! Strength training has been one of the best ways for me to lose some fat, and I welcome the muscles (I take myself to the gun-show now and then!). More muscle will help you burn fat a little faster when you're working out, and will help you reach that fat-burning place during workouts a little easier.
That said, definitely don't over-do it. Seriously. If you're getting sore one day or less after a workout, scale back a little bit. You should be a bit sore the second day after a workout. Don't forget to stretch those muscles, too! It helps with the soreness. And, take rest days. They will help you build up more muscle because it gives your body time to catch up... and you can even do a little bit of light stretching on those days, too!
It's all about learning what works for you! Good luck on your journey, and keep at it!