Whats a good workout regimen to getting those perfect abs and gaining muscle?

my plans for this summer is to start working out becuase I'm slightly out of shape and need to get into the gym but first I need some pointers. My goal is to loose this flab on my gut and get some abs as well as gain some muscle so I was just wondering what are all the things I need to start eating because I never been that much of a health freak so I can really use some guidance for the guys that work out on a daily bases if I can I want to prevent from having to hire a personal trainer so give me what you know. Would protein shakes be a good investment for my goals because I've been thinking about investing in some of that stuff.