The Vikings

I can tell you a bit about the men who came to raid Britain,they were called Northmen (the Danes),the northern english monks who suffered the most under the Northmen never called them Vikings.viking is an activity not a people or a tribe,to go Viking meant to go raiding.
The raids on the christian church is well documented but i wouldnt believe all of it,some sources are very late (13th century chronicle,Roger of wendover).
but a lot of the Great monastries did dissapear ,but i think of this as more of the Danes trying to eradicate saxon culture rather than a direct attack on the Christian relion.
Ivar the boneless and his brothers Ubba and Halfdan are well worth researching,they nearly carved out a new Kingdom for the danes (with guthrums help,of course).
Good luck in your study's

You should be able to find some good books at your local library. Wikipedia (www.wikipedia.com) may have some useful articles as well. A lot of 'viking history' books I've looked at were annoyingly simple, but there are a few good ones out there. Just look for the thick ones, they tend to have the most details