would your introduce some psychology book to me?

Well it all depends on what is your area of interest specifically. In Social psychology of media (and similar), I would definitely recommend Patricia Wallace "Psychology of the Internet". It's not a very recent book, but a classic in the field nonetheless. Additionally I would recommend Manuel Castells if you're inetersted in something more connected to sociology of media. If you're interested in fan culutures, I definitely recommend anything by Henry Jenkins: especially "Convergence culture" and "Textual poachers". If you're intetrested in criminal and forensic psychology then you absolutely have to read John Douglas "Mind Hunter" and "The Murderer Next Door" by David Buss. I hope you'll enjoy those books.

That depends on where you at right now in your study. If you are just starting, get a general psychology book so that you will have a basic idea about your major. The basic theories and principles are stated there and the proponents behind them. If you are into clinical psychology, having DCM is very very important. If you are into fictional stuff, read "I never promised you a rose garden" or "sybil".

You should have the DCM manual with you. That would be most helpful especially if you are already in Clinical Psychology or if you would want to go to Medicine proper.