The Wannier90 user guide and tutorial are both available in the 'doc' directory of the current distribution.
They are also available for download here:
User guide v2.0.1: [PDF]
Tutorial v2.0.1: [PDF]
NSF summer school on materials modeling from first-principles
In July 2009 a two-week school on Quantum ESPRESSO and Wannier90 was held at the University of California, Santa Barbara.
The lectures' videos, slides, and tutorials include presentations on maximally localized Wannier functions and an introduction to Wannier90 (Nicola Marzari and Nicolas Poilvert) can be found here.
CECAM/Psi-k Tutorial on Wannier90, Lyon, France, 26 June 2007
In June 2007 a one day tutorial on PWSCF and Wannier90 was held at CECAM in Lyon.
Introduction to Wannier90 (by Jonathan Yates) [PDF]
Guide to the tutorial examples [PDF]
Tutorial examples [gzipped-tar] (1.5Mb)