This link is to canon's introduction to the benefits of using a Digital SLR. It is well written, informative and has some beautiful shots on it. I highly recommend it if you are a beginner to SLR photography or are considering buying a new camera.
Once you have navigated your way around it, don't forget to return to First Stop Photo!
The videos below (this time from Canon Australia) give you some basic information about buying and using a DSLR. Although they are designed for Canon cameras, they are useful for any make of SLR, although some of the settings that are discussed may come under slightly different names and be found in a different menu!