How to lose some weight?

I gained like 10 pounds over winter... since summer is coming I would like to lose that weight so I look healthy again. I'm not fat by any means but my stomach is a little bigger than normal. how can I quicken my metabolism? how can I lose those ten pounds (and fast)? what should my diet be and should I drink lots of water and do aerobics( I wanna tone up my legs too!) pleasee help :(