A basic scientific calculator. The calculator needs to be able to do roots, powers, logs, and trigonometry. An example of an affordable calculator that will work just fine is the TI-30XIIS
A good pad of graph paper (at least 100 sheets to start with). I personally like the green engineering pads but any kind of graph paper is fine.
A good pencil, some paper, and a folder to keep class handouts in. A ruler or other straight edge is not required but might be helpful for drawings and graphs