Reading Old Norse
There are several reliable online dictionaries, some of them searchable. You can find guidance on these resources by Helen F. Leslie here. The most complete and reliable of these is Cleasby Vigfusson: click on the image to go directly to a searchable version of this dictionary.
The Dictionary of Old Norse Prose is another extremely useful resource, which can be accessed by clicking on the image to the right. The concise dictionary by Zoëga (left) is also perfectly servicable, whilst Ross G. Arthur's English to Old Norse dictionary can be downloaded here, and is useful for basic translation work. If you are finding it difficult to locate a word in these dictionaries, you might try the tips recommended by Helen F. Leslie here, particularly searching the Old Norse to Modern Danish / Norwegian Dictionaries.
Old Norse Online at the University of Texas
The Linguistics Research Centre at the University of Texas at Austin has a series called 'Early Indo-European Online' which includes online lessons for a number of historical languages, including one on Old Norse (developed by Todd B. Krause and Jonathan Slocum). It features a series of lessons introducing the grammar, but perhaps most useful are the reading practices which allow for the testing of what you have learned. This is one of the most comprehensive of the online Old Norse courses on offer.
A New Reader and Glossary
There were many reading groups around the world that were delighted when the Viking Society for Northern Research published its Reader and Glossary (volumes 2 and 3 of A New Introduction to Old Norse, ed. Anthony Faulkes) and made them available online. A good range of texts are represented, and the glossary is easy to use (though a hard copy is ideal for reading groups). Access them directly here and here.
The standard reader prior to this publication was Gordon's An Introduction to Old Norse, which includes several glossed texts following the comprehensive grammar.
Glossed texts and readers are the places to go for those new to Old Norse translation. Another useful resource is the parallel text edition, where Old Norse is presented alongside a translation. This layout allows for comparison with the original. We have several parallel text editions of individual poems on the site, including those donated by Richard North, and there are others available online, including editions of the Viking Society for Northern Research here.
For a more interactive reading experience, Jackson Crawford has some more videos taking students through the process of translating short texts with close attention to the grammar and syntax. One is embedded below: you can view others on his YouTube channel here.