You can find a lot of Chess lessons at this Chess Teaching site, but maybe you are looking for more. One of the sites you may be interested in is Chess Strategy. Especially when you look within the lessons category you may find some very usefull articles. To mention two recent ones: Learning from Classic Games and Delaying The Castle.

One of the cornerstones of chess strategy is a fast development of the pieces and a quick castle – in most cases it’s highly recommended (I’d even say necessary) to accomplish development of the pieces and put a king in the safe place before starting any active operations. There are countless examples of severe punishment in case one of the sides had left his king in the center for the middlegame. However, under right circumstances, delaying castle and starting an active piece play could be very rewarding.

From this last mentioned post I like the fact that There’s always an exception to a rule, in this case the advantage of the fast piece development.

GM Alex Finkel’s article perfectly illustrates this.