how can i make an led flashlight?

i dont no anything about making stuff with leds or anything about led projects, i got 100 assorted leds from a friend who moved, i would really like to make a flashlight with like 12 green or red leds but i dont no what kinda of resister i need or what kinda battery. im completely clueless about this stuff any help would be awesome!!!

Mdob7 years ago
http://led.linear1.org/led.wiz this site is very good at determining the correct resistor and array type.  For a 9V battery input "9" as your "source voltage".  If the LEDs are bright input "3" for the "diode forward voltage" if they are low power in- put "2.1" .  For the next box input "20".  Finally choose "12" as the number of LEDs in your array.  I hope that helped and I hope that you can read schematics.