First off, that drawing is NSFW, disgusting, and quite childish. You should be ashamed.
Second, lol Million_Knives, I try not to talk too long about electronics. Arguably, unlike things like resins or prop-painting techniques, there's a fair amount of well written information sources on the web, so it's easier to just link to it.
Anyway, here's what I know:
A standard button battery is generally 1.5v.
When you hook up a second LED with the leads hanging off the other side, that's known as hooking them up "in parallel". You want to avoid this. Instead, you should hook the long end of one LED to the short end of another, then hook the remaining ends to the battery.
In general a proper LED circuit involves a power source, and LED, and a resistor of the appropriate value. As long as your resister is correct, you can use as many batteries as you want, the more batteries, the longer it'll live, that's all.
If you leave the resistor off, it'll often work alright with one or two button batteries, but it may drastically shorten the LED life, particularly with larger batteries.
Read this link carefully before continuing as it starts to get technical: http://www.kpsec.freeuk.com/components/led.htm
Ya gotta do some math to determine what size resistor to use, and if you are using scrounged LEDs, it can be difficult sometimes to figure this out. The best way is to measure it when it's still hooked up to its original device. First in parallel to determine the voltage drop, and then you cut a wire at the first or last LED and hook the multimeter to the two ends to determine what current the device is running it at. Then plug those numbers into the equation given in the above link.
If any part of the link confuses you, ask followup questions!