When you go to your typical supplement store, you have 4 main protein supplements available to purchase:
1. A whey protein
2. A casein protein
3. A egg protein
4. A vegetable protein such as soy, hemp, brown rice, gemma pea, or alfalfa
Unless you are a vegan, vegetable protein powders aren't a good choice because they have a very poor absorbability by the body.
Egg proteins are a good option but I personally don't think they are necessary if you are already eating eggs/egg whites in your regular diet.
Whey protein is very fast digesting which makes it optimal for supplementing with before and after workouts.
Casein protein coagulates and creates a gel in the stomach. It is very slow digesting which makes it optimal to supplement with before bed.