After lifting weights do I need to be eating some kind of protein? Is it essential to have a snack after or just anything?
While it's not necessary to use a protein powder or some other body building targeted protein product, it IS important for you to get enough protein when working your muscles. You don't necessarily need to eat only protein after a workout, but without protein and water to help your muscles repair themselves, your muscles won't grow and you will experience prolonged periods of muscle soreness.
If you're not after gaining muscle and just want additional strength then make sure you give yourself plenty of rest between training sessions to let your body recover but don't skimp on water. It's one of the great fitness mysteries to people for some reason, but water is essential.
As Scott said, it will be based around what you intend to do and where you want to take your body. Proteins, bcaas and a good carb source are recommended to restore glycogen levels and stimulate protein synthesis in the body following lifting sessions. If you're just doing cardiovascular exercises then protein drinks etc are not essential. A good meal is however.