For this tutorial, you can gather your supplies from a variety of sources. The solar panel I used is from a broken garden light, but there are a variety of options which will work. You should test the voltage and current of the panel before assembly, so as not to burn out your LED bulb, but there is a different Instructable for that! (Linked below)
1 LED Bulb
2 wires (preferrably different colors, for easy identification)
Alligator clips (or other connection method)
Step 1: Identify
Place your solar panel facing down to expose the circuit board (generally found on the back). Identify the locations of the + and - outputs. There may already be wires attached to these points, but if not, you will need to make that connection. In this case, the black wire is - and the yellow wire is +. The blue wire is on the "ground" output, but that is not important for this tutorial.
Step 2: Connect
Clip your wires to each of the points, remembering which color you assigned to the positive and negative outputs.
Step 3: LED
Identify the positive and negative outputs on the LED bulb by looking at the two pegs sticking out from the bulb. The shorter one is negative (-) and the longer one is positive (+).
Step 4: Connect
Clip the wire leaving from the positive (+) output onto the longer leg of the LED bulb and the negative (-) wire to the shorter leg of the bulb.
Step 5: Light!
If your solar panel is already facing up, the bulb should immediately light up. If not, then flip it over! Play around with your light sources to see the effects on the brightness of the LED bulb.
**NOTE: For this experiment, you do not need to add a resistor, but in many cases you might have to in order to prevent an overcharging of the bulb.