Just to be sure, u should make a simple lm317, I am making my first build and have been testing alot, this is the best way to get results, as far as i can tell from my testing..
You dont need extra 1n4007 diodes, potentiometer, 2x10Ohm resistors..
Just see this video..And make a circuit!
DIY: Make a $3 Laser Diode Driver! - YouTube
Now the next thing you'll want is to make a test-load by using 4x1n400x's in series with 1-Ohm resistor(1W~5W)..
This will show you how to set the desired current and measure it.
HOW TO TEST CURRENT IN TEST LOAD:
Scroll down to testload section:
Laser driver - It can be done
Here it is everything you would want to know about making/testing LM317 based drivers.
Dont get confused with difference in components from one Lm317 based driver to another, People often modify Lm317's to fit their diode needs, you just have to be keen on calculations..
Hope i answered the question, and you should really do some more reading, there is a lot of information that you would need to have to make a laser, People here have been answering the same questions many times, every single person comes and puts a silly question which has already been asked.. No Offense, Infact im glad people ask questions, Keeps the forum alive and kicking.. Way to go bud..
P.S: Ghostchrome beat me to it..