The bottom "terminal" should go to ground. That's a real poorly drawn schematic you found!
On the HC14, pin 14 must be connected to the positive terminal on your supply (2v to 6v for the HC part) and pin 7 to ground. You can see that on the datasheet. EDIT: quick survey suggests the Fairchild datasheet is pretty good.
More "Gotchas!":
A small capacitor called a "decoupling capacitor" or "bypass capacitor" should be connected between pin 14 and 7, and placed physically close to the HC14. This powers the chip while it's switching. It takes some time for the power to get from your power supply to the chip due to the inductance of the wires. This is typically 0.1uF.
Unused inputs must be tied high or low or bad mysterious stuff may happen even though you're not using those gates. So pins 9, 11 and 13 (assuming your using the pin 1, 3 and 5 inverters) should be attached to ground or +V. You can do other interesting things with them if you want like paralleling them with your final inverter to boost current. But for now just ground or vcc (v+, power +, whatever you want to call it).