I'm gonna put in another [shameless plug] for
http://www.love2D.org as a good beginner's tool for the following reasons:
1. It's simple to install and run your first program. The following is the entirety of the Hello World program. It is run by pasting it into a text file called main.lua which is in a folder and you drag the folder onto love.exe
function love.draw()
love.graphics.print("Hello World!", 400, 300)
end
2. The engine has a lot of features but EVERY SINGLE FUNCTION AND OBJECT IS DOCUMENTED. They even provide code examples. This is huge to me because I have been frustrated with trying to work with some libraries or softwares *cough*blender*cough* because their documentation was either outdated, incomplete or just plain difficult to work with.
3. The community on the love2d.org/forums is really friendly and helpful.
4. It's adorable. Every version of the engine has an animated screen that pops up if you run the app without opening a project. The latest version has the codename "Baby Inspector" and the "no game loaded" screen is a G-man in a suit and sunglasses in front of a scrolling background of cute babies. This doesn't really have anything to do with why you should use this game engine, I just like it.