Currently reading Viking: Odinn's Child By Tim Severin - full of meticulously-researched material, based on the sagas, and really atmospheric. Also, as you might expect from Tim Severin (re-enactor of Sindbad's voyage among other things) there is a wealth of detail about ships etc. There is also a fictionalised version of a volva's visit to a Greenland farm, remarkably close to the original account (detailed in Nine Worlds of Seid-Magic: Ecstasy and Neo-Shamanism in North European Paganism by Jenny Blain). There are also details of late Irish paganism (or the remnants of it that survived in hiding).
The only problem is that the book is unputdownable!