Not specifically for Source, but just in general. Where’s the best place to begin?
well, pick your poison first. if you want to release anything commercially i wouldn’t pirate software. i use blender because its free. and i mean usually you can find some tutorials on the basics then just work your way up. youtube is a pretty good place but nothing can compare to a mentor that can work with you. but i don’t know many people that do that.
If you still can, take a course in school. It’s where I learned what I know.
Watch tutorials, don’t just play about in the menus. You’ll find you will learn a hell of a lot more this way, watch tutorials from a few different people as everyone has their own preferences and approaches to modelling.
Or you could get 3ds max for free if your a student.