A nice reference to the basic Scrum vehicles Epic, User Story, Sprint and Version can be found at Atlassian’s article Epics, stories, versions, and sprints. When having to explain them to new agile developers/managers/product guys, this article might be worth a read.
Backlog grooming in Scrum may be misunderstood, and this post explains what is a sensible approach to this activity.
If you’re searching for a very good introduction to Scrum, I recommend the following book: The Elements of Scrum.
The book is nicely written, contains all necessary information for beginners, and is not too long to be boring. Have a look.