Moisturizing hair

What’s the right balance of protein and moisture for hair? Can a stand test really tell you what your hair is asking for? My hair is brittle, breaks easily. This would indicate a need for moisture, right? What is the best way to moisturizer hair, deep conditioners, hair mask? How often should one do these deep treatments on hair and for how long? And any recommendations on hair products that would help restore moisture to my hair?