I don't have a diagram handy, but its pretty simple. You need:
Either a ceramic resonator (with three pins), or a crystal and a couple 18 picofarad capacitors. If you're using the resonator, connect the two outside pins to pins 13 and 14, and the center pin to ground. If you're using a crystal, connect the two legs of the crystal to pins 13 and 14. Connect one leg of each capacitor to each leg of the crystal, and the other leg of each capacitor to ground.
You should have a 0.1uF decoupling capacitor between Vdd and Ground (pins 11 and 12). On a 16F877, I normally put one there, and one between 31 and 32 as well.
You should have a 5-10K resistor between pin 1 and Vdd (power).
That's all you need.