A colleague of mine had found a great case study about how Scurm and XP are used in anonymous SW company in Stockholm. This paper called Scrum and XP from the trenches - How we do Scrum by Henrik Kniberg is a good introduction to usage of XP and Scrum and a great example on one way to use these together.
I found it especially useful because the down to earth grip on methodologies, practical insights and taking in to considerations both the technical and the business side. This all in about 100 pages of easy to read and entertaining text. Also Henrik's blog is a blog worth visiting.