It tingles and burns a little at first. Then you feel the nicotine very quickly. As soon as the tingling and burning has died down, and even some before, you smell the snuff's "flavor". It is a very intense smell sensation that lasts for around 30 minutes. It is almost as if you are tasting with your nose. Snuff comes in many flavors such as strawberry, tangerine, rum and maple, cherry, medicated (with eucalyptus or some other ingredient to open the sinuses and give a refreshing feeling), and coffee.
It does give you an energy boost. It is the nicotine that does this. After I use snuff I'm usually in a great mood for about an hour from the nicotine.