The Online Icon Support centre:
Russian Icons
Free Old Church Slavonic fonts
http://www.wazu.jp/gallery/Fonts_CyrOCS.html
http://babel.uoregon.edu/yamada/fonts/ocslavonic.html
http://clover.slavic.pitt.edu/~aatseel/fonts/wincyrillic.html
http://www.davidzbiral.webzdarma.cz/cyrillicof.htm
Online Church Slavonic lessons
http://justin.zamora.com/slavonic/
http://www.orthodoxepubsoc.org/etutorindex.htm
http://www.utexas.edu/cola/depts/lrc/eieol/ocsol-TC.html
Online Church Slavonic Institute
http://public.srce.hr/staroslavenski-institut/en/home.html
Corpus Cyrillo-Methodianum Helsingiense (An Electronic Corpus of Old Church Slavonic Texts): http://www.slav.helsinki.fi/ccmh/
Greek Icons
Roman Icons: