Here are some good introductions to Scrum methodology:
Page at Wikipedia (link).
Scrum.org (link) hosts Scrum Guide, which is an essential reading for Scrum practitioners, and assessment tests as well as videos.
Scrum site (link) at Eclipse.
How to implement SCRUM in 10 easy steps (link).
A (video) presentation by Jeff Sutherland (link) at Google.
Check Scrum Cheat Sheet or see the one attached, below.
Scrum Papers (link) has a great overview of Scrum in the first chapter, Introduction to Scrum. By Jeff Sutherland.
Scrum Training Institute's library (link) contains useful material, including Jens Ostergaard's presentation in why Scrum is hard.
from Jeff Sutherland's presentation (link) on Scrum.
You know you do not do iterative development when:
You know you do not use Scrum when:
See attachments for various artefacts related to Scrum.