After reading the wiki page on Enigma's, I am still confused as to how it works. Are there some sources that run through how the enigma machine works that is easy to follow. Which also gives information about the how codes are encrypted and decrypted?
In this (non mathematical) book, you will certainly find what you want.
Here we find a simulation (step by step) in Flash for an enigma, that you can play with yourself (change rotors and steckers, see what input corresponds to output). I think the wheels are non-historical, but the principle of an enigma becomes clearer. This site has a Windows program with an exact simulation of an historical machine, which could be nice to play with.The cryptomuseum site has a nice overview of historical machines.