In the tables below, a dot( . ) represents a short signal, be it a tone, flash of light or other, and a dash( _ ) represents a longer signal.
It's handy to note some of the easier letters to remmeber, for example, the letters E, I, S and H are made up from one dot, two dots, three dots and four dots, while T, M and O are made from one dash, two dashes and three dashes respectively. Most of the letters can also be paired off with their opposite, or mirror.
Choose one of the methods, but not both.