Hey what's up everyone, I came across this article on another website and thought it would be interesting to post here for any who are interested in mod development.
It's a tutorial of 27 videos by design3.com but at the following link you don't need to register on the site to view the videos(of course you should if you enjoy their method of teaching and are serious about it).
Source SDK: Making a single player mod
I haven't had the time to work through it yet since I am currently bogged down with schoolwork and still more interested in writing my own games. As soon as I get through my courses this semester I will take the dive and make something myself but I hope you find some valuable information here.