use those diodes for testing or practicing. You might even see, with a magnifying glass, a mark on the tiny tiny rectangular die to tell you which is (+) and which is (-)
Ok its not so much of a mystery at this point i spent a few weeks trying to find this information but here it is. Now i dont totally understand this so im hopping one of you do, were do i connect + and - to this thing RLD78MRA1 | Laser Diodes | Laser Diodes | Opto Electronics | ROHM CO., LTD.. and at this point i understand that it is a low power and ir but you have to start somewhere right.
I would just practice soldering on the diode, and not bother trying to hook it up. Like Tikilaser mentioned, that's an IR diode, and the only conditions in which you'll even see the faint dark red are those where your eyes will be exposed to dangerous levels of IR. Just toss it and get a visible laser diode.