Many of you will probably be familiar with the HolyBooks.com site, it offers free downloads of books from loads of different traditions but these are some of the more practice-orientated titles I've read lately. They're from various traditions but are full of really good instruction in straightforward terms, and some have good descriptions of the symbolism that I haven't come across so clearly anywhere else.

A Guide To Shamatha Meditation
Keeping the Breath in Mind & Lessons in Samadhi
Making Sense of Tantra
In This Life Itself
The Anapanasati Sutta - A Practical Guide
Knowing And Seeing
Art of Attention
How to Develop Metta
An Introduction to Mahamudra

I'll leave the list here just now, these are just some of the ones I've read recently and thought were worth linking to.