I got this book that might be useful to you guys (or musicians in general): “The Art of Practicing - A guide to making music from the heart” by Madeline Bruser, published by Bell Tower.
It is a book that gives lots of practice and performing tips, like how to connect with your audience and gain energy by acknowledging their presence rather than by blocking them out, what would be a positive attitude for practising, etc. Many skills are covered, including listening, memorisation, posture, expression, etc. Theres lots of nice pointers in there that make it a really good book for the novice or experienced musicians.
Although the anecdotes are usually about classical musicians because the author is a classical pianist, the ideas in there are very universal and are all applicable too all kinds of musicians. I highly recommend this book to those who are interested in horning the non-technical aspects of musicianship and practice. At about US$12 its extremely good value, and the advice offered in there is often priceless. Check it out at your local bookstore or at http://www.amazon.com