Since I have recently delved into this topic, I want to share my blog posts (Spanish/English) about this fascinating method developed by Ärvo Pärt. I always try to write these posts from a simple and practical point of view.
In English there are some videos available on you tube, and also the text by Paul Hillier, but in Spanish there is nothing.
Tintinnabuli. (I): Essentials
Tintinnabuli (II): T voice
Tintinnabuli (III): M voice
Tintinnabuli (IV): Adding T voices
Tintinnabuli (V): Adding M voices
Tintinnabuli (VI): Adding complexity
Tintinnabuli (VII): Addendum
Example: