ok here is how I always remember what is what: there is an anode and a cathode, the anode is the big part of the triangle in the symbol. So anode = A$$ or butt of the symbol. Cathode is the Line of the symbol, generally when the part is marked on a diode they mark the Cathode with a dot or a line(just like the symbol), which in an LED's case is the negative lead.
+ Anode -|>|- Cathode -