Hey, I'm trying to change out the head gasket on my car, but have no experience with performing auto repair and maintenance, I was wondering if anyone has any pointers or tool suggestions that you might think is useful for me.
Seriously, before you even think about software you should sketch out some rough ideas with pencil and paper.
I agree with what D3v1L80Y said, but you could always download Inkscape, it's free and allows you to create a vector image. You can also draw something by pen/pencil, scan it, and vectorize it. It gives you a start at least.