Thanissaro Bhikkhu

Thanissaro Bhikkhu is an American monk in the Thai Forest tradition. Abbot of Metta Forest Monastery since 1993, Thanissaro Bhikkhu is a promiment scholar and academic as well as monk. His translations of the Pali Canon can be found at AccessToInsight.org.

His teaching style is breath-focused. Unlike many other Theravada teachers, he teaches involvement with practice rather than bare observation. He teaches comfort, exploring the breath in the entire body, investigating cause and effect, and jhanas as important for developing insight.

Resources

Access to Insight - A collection of suttas and study guides from Than Geoff and other teachers. 

DhammaTalks.org - A site full of talks, translations, and books. Many are from Thanissaro Bhikkhu, but there are other teachers and translators as well. 

With Each & Every Breath - This is perhaps Than Geoff's clearest manual for practice. It starts with traditional instruction, and then incorporates the method of practice he learned from Ajaan Lee Dhammadharo.