Have only skimmed it myself, but you might be interested in Analysis of web-based tutorials created by academic libraries, The Journal of Academic Librarianship, Volume 35, Issue 2, March 2009, Pages 126-131 (doi:10.1016/j.acalib.2009.01.010).
Abstract: This paper aims to analyse the characteristics of tutorials created by academic libraries. It evaluates a sample of 180 tutorials by applying thirty basic indicators referring to general characteristics, content, teaching methodology, usability and technology. The general conclusion is that most of the tutorials are at an early stage of development.
Conclusion: If academic libraries wish to increase their role in all aspects of education, they must provide high-quality tutorials.
I see the ANTS project is one of the samples.