Hey Man it's pretty easy, I looks like you have 2 batteries, a switch, 1 LED, and I think the black was the casing for it? Anyways, if you look at the LED, it has 2 leads (wires). One short and one long. he cathode is the short lead and the anode is the long lead. Connect the Anode to the positive side of the battery and the Cathode to the negative side of the battery. Like this
Battery LONG LED
-------- ---------------------------------
| + | | \
| | | |
| - | SHORT | /
-------- --------------------------
Now if you want to put the switch in the circuit that's easy too. Like this:
Battery Wire Switch LONG LED
-------- ------------------- ---------- -------------------------------
| + | | | | \
| | ---------- | |
| - | Wire SHORT | /
-------- -------------------------------------- --------------------------
hope this helps you out, peace-