I'm a very procedural programer however I've fallen in love with object oriented, but now the way I have my files setup for my programs are kinda hap-hazardous.

I haven't found any examples of file system layouts to get me on the right track.
So if any one can help me that would be a great educational boost for me, also what are the recommended file types and how would they be used I know some people use .tmpl and others .lbi I know what they stand for but as for usage not so much they seem interchangeable.