The symbol below represents an op amp. The top input is the inverting input VI, the bottom is the non-inverting input VNI. The two vertical lines marked VCC and -VCC are the op amp's power supply, and are usually connected to the positive and negative power rails (voltages range from around 4-15V), although a couple of circuits (eg the integrator) have the power supply connected to positive and zero voltage rails. VCC is an abbreviation for 'supply voltage'.
VCC
|\ |
| \ |
VI -----|- \
| >--- VO
VNI-----|+ /
| / |
|/ |
-VCC
There are many different configurations of op amp. Here are a few configurations that may come in useful.