The tutorials are easy to read and understand, but there's a lot of copy and pasting involved, so don't expect to become a programming expert by working through them. They don't always go into great detail, but it's usually simple enough to figure out what you're doing and learn from it.
It's certainly worth checking out if you have any interest at all in creating games, especially if you want to make some quick cash by doing it. New developers that upload their games to Kongregate and get good ratings have a chance to win up to $250 in their contest. I doubt I'll be making any prize winning masterpieces anytime soon, but I will be keeping up with these tutorials and seeing what kind of cool games I can create.