Here are some links and references to other websites and books.
Kind of what this website is based on, but much more polished and complete.
Almost 50 years old, but still relevant as there is almost no new research being done on mosses. You will need a glossary.
1300 Terms Explained and Illustrated
has many references to Bryophyte resources
has a nice introduction to liverworts and mosses, if you have an attention span
upload and identify observations
A beautiful, well-made website with hundreds of plants, mostly from New Mexico. Includes most of the plants commonly seen here.