At my school, Physics majors are the only ones who HAVE to take PDE, math majors and engineers have the option as an elective, but none of them do that because it has the reputation of being the most difficult math course at my school. I'm going into Calc III in the spring, then DE is next. What's a good book for me to get acquainted with DE and PDE in the meantime? I'd prefer something that would give me insight on how they work, the problems they are meant to solve... nothing too proof heavy, and a lot of plain english and not just straight math throughout. Any suggestions?