Need some guidance on as3 basics

Ok, I’ll say right off that I’m just starting to learn as3. I wanted to start with a simple project so if anyone can just post here or point me to a tutorial I would be grateful.

I want to start a line in the corner and wherever the user clicks and drags, the other end of the line follows. Do you know what I mean?

Should I be using the drawing api for this? I would like to learn the right way to make sure performance is as fast as can be.

thanks in advance, you guys all rock.