John Hobbins links to three great introductions to the practice of psalm-singing in Christian worship and prayer:

• Singing the Psalms: A Short History by Elizabeth Liebert
• Singing the Psalms: A Brief History of Psalmody by Richard Leonard
• On Singing Psalms by Richard Leach

David Koyzis has begin a new blog dedicated to the Genevan Psalter and Psalmody in general.

If you’re interested in some practical steps to incorporating psalm-singing into your devotional life, Cynthia Bourgeault’s Chanting the Psalms is an excellent introduction with accompanying CD to teach a variety of simple tones. I’ve reviewed it in some detail beginning here.