Just thought I might as well post some links and stuff that may be of use to you.
Although before the time of the mod, this map shows the extent of the monasteries in Ireland in AD 650 as well as a lot of other related information. It is my understanding that some Irish monasteries tended to be quite basic, even wooden, so you might only want to represent them as lesser buildings. In VI2 I used abbey-priory-monastery as the building tree level names.
http://www.wesleyjohnston.com/users/...istianity.html
There are various and numerous useful maps here:
http://www.anglo-saxons.net/hwaet/?do=show&page=Maps
This is an interesting map from a genealogical site:
http://www.clanlindsay.com/kingdom_of_lindsey.htm
Good anglo-saxon/viking live research site:
http://www.regia.org/main.htm
This is an excellent source of names from the period (most cultures and kingdoms) and includes all the special characters over letters of the alphabet:
http://www.s-gabriel.org/names/
That's the more obscure stuff - I'm sure you have found lots of other stuff that we also used from such sites as wiki etc.
Hope this helps.
I of course expect TLK to be to M2TW what VI2 will be - and is becoming - to RTW
Long live viking mods (because most of them have died) !