Hér hefur upp og segir frá þeim manni er Sigi er nefndur og kallaður að héti son Óðins.
Byock translates the first part of this sentence as : Here we begin by telling of a man who was named Sigi....
For that matter, the whole of the this first part of the setence is a bit difficult and I would be interested in hearing some thoughts on the construction of it.
regards,
Alfta