I found this book funny, but I also found my previous courses in Physics entertaining, as well, so that is only to be expected. It seemed like as reasonable a primer on waves as I could find without consulting anyone directly for help.
There are waves all around us, and this author explains what he knows about them without getting too technical. Maybe a little technical, but not terrible, and there's always recourse when stuck. TI-81s not required.
A short introduction with a lot of math, but with much discussion on what is going on. This is a deep enough subject that even a supposedly simple introduction is plenty complicated, and it would take a LOT of study to understand it very well. I went through this quickly to get a feel for the subject, mostly to better understand a vibration problem I have on my job. This book did help me with that.