I don't work at a software company, but have taught myself C# and have been using it fairly regularly. Now another engineer in the office (not a software engineer) has expressed an interested in learning to code like I can. I'm helping him through some simple console applications, but he's having some trouble grasping all the OOP concepts. He's an engineer so he's had experience with procedural programing in school, but the concept like objects, classes and instances are really challenging him.
I suggested he get the Head First C# book, but I was also wondering if anyone knew of any good tutorials on line that explained OOP principles. He's using C# but it really could be language agnostic. Also something with a lot of pictures and diagrams would be the most helpful.