Exercises to help my sides and tummy shape up for summer?

im a 20 year old girl, im not really chubby or anything, and i dont really have lovehandles, but i do have a bit of a pooch on my stomach and my sides do go out more then they used to, so i was wondering if there are any good easy simple exercises to help shape up my tummy and make it flat, and also slim my sides a bit before swimsuit season:) ...anyone have any good ideas?