There are serious amateur astronomers, and then there are serious amateur astronomers. Alan Chu is apparently one of the latter. Based in Hong Kong (which I don't imagine ever has the best seeing or sky transparency in the world), he has some great images of Mars on his "workshop" web page. But his masterpiece is a free 225-page PDF called Photographic Moon Book (version 3.1). The book is a detailed photographic "tour" of the Moon, with over 250 original Moon images (extensively labeled), excellent diagrams and explanations, and detailed notes on observation and imaging techniques. This is clearly a labor of love, and also a work of great beauty and quality.
It is also a huge download - 100 MB! I learned about it in an email newsletter from NSS, which references this U.S. mirror site, which has given a "403 Forbidden" error all day today, perhaps due to traffic. So I went directly to Alan Chu's own Hong Kong-based web page, and the download took about 3 hours!