Don Blake (AKA Thor) is the chief scientist of Project Thor, the owner of the Asgard Night Club and the second-in-command of the Avengers, surpassed only by Nick Fury.
Born Donald Blake, he was a child prodigy in science and maths. Over the years, he received lots of gifts from his parents because he recieved lots of prestigious award. Taking apart the gifts and making them into something better became a hobby.
Upon graduating from high school, Donald was confronted by Nick Fury to work for S.H.I.E.L.D. His first assignment was the Electro Initiative. For a short time he acted as the super soldier Electro for the goverment using the fake name Max Dillon. It was this that lead to his next project three years later, Project Thor.
Project Thor took a year to complete, after which he took on the mantle of Thor. He used the electricity controlling abilities of the armour and hammer (based on Mjolnir, Thor's weapon in mythology) to supply power to poor towns.
Donald legally changed his name to Don after being asked to join the Avengers Initiative as he believed it would be a more popular name than DOnald when his identity was made public.