A document that I was privileged to access pre-release snapshots of has now been published:

Introduction to Chinese Chess (Xiangqi) for International Chess Players A Comparison of Chess and Xiangqi By xq_info(add)gmx.de (a bit shy about his real name) 98 pages

You may like the self-assessment puzzles aspect about it, but not only that. Recommended! It's up here:

http://wxf.ca/wxf/doc/book/xiangqi_introduction_chessplayers_20150323.pdf

Best, Sebastian