Ah! Electronics coursework! Please help if you can!?

Find the actual number of the chip. I don't think it's DIL 18, that just means it's a dual in-line package with 18 pins. Once you have the actual designation, use Google to find a data sheet. It will show the pinout of the chip, explain how it works, and maybe even have a circuit for building a timer. Or call up where you bought the chip and they might have a data sheet.