Torr is right. Flash is not something that is as easier to grasp as html. The scripting language use in Flash is Action Script. But its more used for high level of complexity and interaction in your Flash movies.
This is my favorite site:
http://www.flashkit.com/index.shtml
Check out the movie section where you can actually download the source files to mod. You name it, banner ads, websites, games, anime, etc. its all ther for you to download. This will really help you out as a begginer.
Good Luck!