The best way I learnt was to actually take photos with my SLR! I'm not someone that looks at the manual and instructions, I often ditch them and try to learn myself. Learn your camera first, how it works, how to change the settings, how to switch to different modes. To supplement this, I would start with some of the links suggested above regarding exposure and the relationship between ISO, aperture and shutter speed.
Personally, I would stay away from the strobist 101 blog initially as this is to do with different kinds of lighting if you have at least one flashgun (which I am assuming you don't have at the moment). Stick to the basics of photography and once you've done that remember to keep practising!