Hi Ed,
There are a few dictionaries available online.
A Concise Dictionary of Old Icelandic by Geir T. Zoega
http://norse. ulver.com/ ondict/zoega/ index.html
...which is abridged from An Icelandic-English Dictionary by Richard Cleasby and Guðbrandur Vigfússon
http://www.ling. upenn.edu/ ~kurisuto/ germanic/ oi_cleasbyvigfus son_about. html#images
Ordbog over Det gamle norske Sprog by Johann Fritzner
http://www.dok. hf.uio.no/ perl/search/ search.cgi? appid=86& tabid=1275
Altnordisches Wörterbuch by Gerhard Köbler
http://www.koeblerg erhard.de/ anwbhinw. html
The Icelandic Online Dictionary is a dictionary of Modern Icelandic, but also useful to anyone interested in Old Norse. It's based on Íslensk-ensk orðabók / Concise Icelandic-English Dictionary by Sverrir Hólmarsson, Christopher Sanders and John Tucker
http://digicoll. library.wisc. edu/IcelOnline/ Search.TEId. html
And for poetic vocabulary, there's Lexicon poeticum antiquæ linguæ septentrionalis: ordbog over det norsk-islandske skjaldesprog by Sveinbjörn Egilsson and Finnur Jónsson
http://www.septentr ionalia.net/ lex/index. php
And Eysteinn Björnsson's site Jormungrund
http://www.hi.
is/~eybjorn/ ugm/
For Old Swedish, Fornsvensk lexikalisk databas includes Ordbok Öfver svenska medeltids-språ ket by K.F. Söderwall, K.F. and Ordbok till Samlingen af Sweriges Gamla Lagar by C.J. Schlyter.
http://spraakdata. gu.se/sdw/
Old Danish, Ordbog til det ældre danske sprog by Otto Kalkar
http://www.hist. uib.no/kalkar/
There are more links in the links section of the Yahoo Groups Norse Course website, and here [ http://www.oe. eclipse.co. uk/nom/norselink s.htm ]. In particular, see the sections Dictionaries, Reference and Beginners. The last section includes sites with courses such as Old Norse Online [ http://www.utexas. edu/cola/ depts/lrc/ eieol/norol- TC-X.html ], which can also be used as a referrence grammar.