You need a certain amount of protein each day...more if you are working our harder. Read through these forums and you'll find more info as there have been several threads on the subject.
Personally, I drink a shake with fruit, milk or soy milk, flax meal (for Omega-3)and malted milk powder for breakfast unless I'm eating oatmeal. Then I drink just a protein shake later in the morning. On the shake for breakfast mornings, I eat some fiber like granola mid-morning, just as a snack and to get some fiber. Mixing milk makes the protein absorb slower while water makes it happen fast.
I find if I have protein in the morning (and a small snack mid-morning) I'm not so ravenous by lunch.
Also, I drink a protein powder and water shake after working out. I feel this aids in recovery and cuts down some on muscle soreness as the protein help the muscles rebuild. Of course, I could be full of crap!
My favorite powerder is ON (Optimum Nutrition). You can find it at
www.musclesurf.com