The short answer is that if your hair is dry and damaged, you need to do deep treatments and add protein (for the damage) to your hair's diet. If you do a search here for DTs and PTs, you'll find more information.

The longer answer is that we'll be much better able to help you if you'll tell us your hair's texture (on a spectrum of fine to coarse) and porosity (low to high, with low meaning it takes a while for your hair to soak anything up).
Peace,
Morgan

Baby Fine 3B, low porosity, normal density and elasticity
CGing since July 2008