First you have to find how much protein u need r u weight training with heavy weight how often if yes u may need 3/4 to 1 gram per lb u want to be in weight have some protein 1/2 hour before u workout than with in 1 hour more protein some carbs will help speed absorption.
If u not getting enough protein from regular meals whey protein is a good choice
Don't just assume you have to go buy something because you are skinny. Are you skinny because you have no muscle or are you just not a wide build? I am pretty skinny, but I also have muscle. Are you talking about waist skinny or overall?
U can get enough protien from the right type of meals but if u want to be a body builder type of guy try muscle milk but u have to lift heavy or do instense workout for any type of protien powder shakes or pills .