Hi Twinklestar, a few of us are using Mr Chan Kai Yao =P He's quite a popular JP. Else U can refer to the ROM website for a list of JPs.
U can lose weight by cutting down on the amt of cardo u eat. It helped me =) But of coz it's not that u totally lay off carbs, just cut down. Coz ur body still needs some carbs to function properly. If you are planning to not eat carbs totally, then make sure you only do it for a while, like 2-3 mths.
Sit ups are only good for toning the muscle, if u have a layer of fat above it, doesn't really help =P U'd need cardio to remove that.
Squats help tone the legs and butt area but some say it makes their butt bigger so not sure =)
Skipping is good for cardio but be careful if u have weak joints and stuff, better make sure u use with shoes...
I initially went to the gym with my FH at least once a week to work out but I mainly did weights not much cardio. Then I signed up for a cardio class at the CC near my workplace and I found that helped. So U can try those =)