How Can I build muscle by a healthy diet?

I'm a Navy DEP recruit and I plan on joining the SEALs after Officer Training. I have been told by some ex-SEALs that I need more muscle if I'm planning on going to BUD/S but I need to know, what foods have the protein necessary for building muscle? and, if you could be specific, it'd be much appreciated. I would also like to know if certain fruits/vegetables help as well or do they all in general. Please type in what foods (meats, breads, etc) are the ones that help the most for muscle building.