Another good blog from a Frenchman (written in English). This is quite advanced, but he also provides an excellent pdf file of component colour codes, markings and pinouts (that are easily forgotten, and when you get older you have to use a spyglass to look at them closely (though it is not simply because we are old, component sizes have changed 3 times in my lifetime, getting smaller at each change)
Arduinoos
http://www.arduinoos.com/wordpress/wp-content/uploads/2013/10/Electronics-pinout-sheet-rev1.pdf
