Something you should be very mindful of while teaching your brother to program is for him not to rely too heavily on you. Often when I find myself helping others they will begin to think of me as answer book to all of their questions and instead of experimenting to find an answer they simply ask me. Often the best teacher is experimentation and every time your brother has a question like "What will happen if I add 2 to a string?" you should tell him to try it out and see for himself. Also I have noticed that when I cannot get a concept through to someone, it helps to see some sample code where we can look at each segment individually and explain it piece by piece. As a side note people new to programming often have trouble with the idea of object oriented programming, they will say they understand it when you teach it to them but will not get a clear concept of it until actually implementing it.