Or learn it along with him at his blog:
My name is Justin Zamora, and I am learning Church Slavonic, the liturgical language of the Russian Orthodox Church. I created this site in order to learn more about the language. Since my knowledge of Russian is limited and there are few English-language resources for learning Church Slavonic, I decided that having a web site where I could put my notes and ask questions was the most practical way to increase my knowledge of Church Slavonic.
He’s got very useful tables and explanations, and he lets you know where he doesn’t have the info; in the Diacritics section, for instance, he says of the kavyka “This mark is quite rare. It comes in pairs and appears to act as some kind of a delimiter. I have no idea what it means.” (If you do, let him know.) He has a section of Grammatical Analyses of texts and one of Quizzes and Tools. Lots of fun. (Via PF.)