Another Forgotten Book

Long ago, a friend loaned me a book.  I think it was new in '96 or 97.

It was a science-historical-fantasy novel about a Viking kid.

Things I remember:

There was a bad guy who had had his arms and legs cut off by the Vikings.

The symbol for the kid's god was a ladder.

And a scene where they "christen" a ship by running it over captives on the runners so the blood would sanctify the launch.

There's a scene where they get visions from drinking some icky concoction then again when they drink the piss from that...

And that is about it.

It was apparently the first book of a trilogy.