transistors

http://fourier.eng.hmc.edu/e84/lectures/figures/transistorBJT1.gif

the transistor has three points,the base
the emmiter and collector.
the voltage of the emmiter is higher than that of the collector when measured

the above is two diodes i tied cathode to cathode to form a P-N-P transistor

to test transistors set the multi-meter to the diode test. a transistor is pretty much two diodes connected together anode to anode N-P-N or cathode P-N-P to cathode.so once you have established the common connection you can determine which is collector(lower voltage) and emitter(higher voltage).