Will I lose weight if I do this for 3months aswell as doing weight and sit ups will I look good?

No. Hate to say it but, count your calories. Work from what you're on now (say 2000) and gradually lower it depending on what BMI (BMI calculator) you are. Start eating more regularly, I suggest a self-tailored meal plan. The basics of your diet should be no junk food or sodas, lots of water and high protein meals. Highly recommend this website, my friend designs tailored meal plans, quote CASSIE and he'll give you a basic pack for free.

http://www.startupdietadvice.com/#!SIGN UP/c19rm He's currently redoing some features of the site, but this link takes you to his ask box, email him and he'll take you from there!

Regarding sit ups, they are useless. Running and other forms of cardio are brilliant for lowering your Body Fat Percentage (Mass) however, sit ups will hinder weight loss as you are tearing and broadening the obliques. I recommend push ups, squats, dumbbell fly's etc. This helps shape the back and chest (Your traps, Triceps, Pecs & Deltoids)

Check out Elliot Hulse, (YouTube) He's probably just what you're looking for. Hope this helps!

Slide a modest trampoline under your couch and pull it out for Property of Cards marathons.

Turn on tunes and dancing while cooking.

The the very next time it snows, up your karma as well as shovel your neighbor's sidewalk as well.

Turn on tunes and dance while cooking.

When you need to be able to brainstorm, do it while walking.