looking for recomendations

Does anyone know of a book I can read, or a class I can take that would help me learn how to effectively deal with different personalities? Like a managment class or something? I work with a great team of people, who all have different communication styles and who all work and are motivated differently. I'm trying to figure out how to best work with them all collectively and individualy. For instance: Man #1 has the most negative attitude ever, and does not realize that others pick that up, prospects and co-workers. He is spot on in every meeting but after the meeting has nothing but negativtiy to bring to the table (It doesn't matter they won't sign the forms anyway type of attitude) I figured it out today, he doesn't like people, which, if you think about it, is completely uncharacteristic of a sales position. He doesn't want to BS with people or talk to people, he only wants to get them to do what he wants and quit. There isn't really a single person on the team that communicates well with him or that considers him valuable. So I'm trying to 1: train the team how to deal with him 2: learn how I can better work with him instead of shutting down or letting his negativity spread to me when we have to spend the whole day together and 3: try to somehow show him that his attitude comes through in all he does and says. OK off to a present a seminar on the difference between ROTH and Traditional investing and what it means for YOU! Sounds fun, huh!