>>9155
Scratch is actually quite a nice tool. It teaches core programming concepts (variables, procedural execution, conditional statements, loops, etc.) and has audiovisual capabilities. Really it can be thought of as a language with powerful input and graphical libraries built into it. I've seen people create 3D physics engines and raytracers using Scratch before.
I skimmed through that CS50 course out of curiosity about two weeks back and it looks abysmal. Scratch is easy enough to learn on your own and if you're going to study C you should use King's book. Its quite high quality and is more than enough of a reason to choose C as a first real language (Yeah, not to many people think of the available educational resources and their quality as a reason for choosing a language, huh?). I have no idea what the state of Python education is and I'm not really all that interested in learning it until I have to, but its a simple enough language that I think most resources will be alright. HTML, CSS, and Javascript can be learned on w3schools.
Big word of advice: If this is your first time learning a language, keep track of important terminology. With C for example keep track of words like "Variable (also known as Object)", "Declaration", "Statements", "Assignment", etc. as you first start off. The list will build up extremely quickly and it'll make understanding the language and its standard easier (if that's what y