And I want to write about the Arduino's History, something as the boards release date. But I had been searching in the website and internet and I had not found anything.
There is some history on the hardware reference page: http://arduino.cc/en/Main/Boards
(For instance, it says that the first manufactured Arduino was the V2 serial, which began manufacturing in 2005.)
I looked at wikipedia and was somewhat surprised to see that they had something of a history, but no dates. They are sometimes a good source for such things. Perhaps once you've pieced the information together, you could update the wikipedia page with the data? Arduino - Wikipedia