One of the most common questions for beginners is 'why should i shoot in RAW?'. The only disadvantages to shooting RAW are file size (storage is cheap these days) and the fact that you need more specialist editing software to work with the RAW files, i.e. Adobe Lightroom, Apple Aperture, Adobe Photoshop, etc (most people shooting with a DSLR most likely will already be using software that can read RAW files) so I don't see either of these issues as a problem, the advantages of shooting RAW far outweigh these.
Here are a couple of links to articles that go into more detail about RAW files and some of the reasons to shoot in that format:
On our training courses we go into detail about RAW shooting and focus on the software that helps you get the most out of your RAW files, details of our workshops and training can be found here: