One of my personal favourites is 'Living Buhddha, Living Christ', but all his books are great (you can find them all on Amazon).
On his website, you'll find the 'Stillness Buddy' software that you can download onto your PC. Yes, even Bhuddist Monks have turned to technology! The software can be programmed by you to send messages on your screen as often as you wish throughout the day, reminding you to take 'mindfulness' breaks, moments lasting only a minute or so where you breathe and balance yourself. Those of you sitting behind your computers all day would love this! Click this link to download a free 14-day trial: http://www.plumvillage.org/stillness-buddy.html
About our Teacher Zen Master Thich Nhat Hanh (Thầy)