What exactly is the Tour de France? Is it a marathon?
It is a bicycle race completed in multiple stages - it is held in France, though the bikers sometimes pass through countries that are nearby
What other countries does the Tour de France pass through? 
I'm not too sure, but I do find it interesting that it has been held every year since 1903, except for when the two World Wars were going on.
Tour de France
The race came to be as a method to increase sales for  the newspaper "L'Auto"
Wow, that's interesting. Do you happen to know what is the fastest completion of the Tour de France. My guess is Lance Armstrong?
I don't know if Lance was the fastest ever, but he did win a record seven consecutive times from 1999 to 2005.