Help Please!

He wants to learn to sketch and draw. I am completely clueless. I went and looked through amazon and saw several books, but I don’t know enough about it to make a good choice for an adult with some communication issues could follow. I am hoping someone here could recommend some good books to get for him. I know it’s a long shot, but there are so many here I am hoping someone will have some suggestions.

He is a great reader. He can typically follow written instructions. He really needs something to challenge him.