I don’t know of any decent courses off hand. However, I can tell you that the best thing you can do is to just go out and shoot. Experiment with different apertures and shutter speeds. Try out different lighting situations.
I’ve become (IMHO) somewhat decent at photography and it was largely through self-learning and lots of reading. There are plenty of photography learning sites (Digital Photography School is pretty good) that have lots of free content dedicated to helping people learn photography.
The Wolf