I'm looking for any/all resources related to Tir na nOg, the Danaan Families and their history.

Well, there's the Tir na nOg book itself, obviously. Then there's the section for it in Shadows of Europe, and finally its entry in Sixth World Almanac.

No idea if there's anything else; frankly, the other Tir has been getting more focus in terms of the more recent products.

Anything in Elven Blood?

*dips two fingers into the cooling pool of elven blood and tastes*

Hmmm.. little high in copper, low in iron, but pretty much the same.

The London Source book gives like 3 pages to Tir na Nog, so a lot there either.

I think the novel that had some Tir stuff in was Worlds Without End (Caroline Spector)...Harelequin and Aine story, so not to everyone's taste...I like the IE stuff personally and the links with ED...

(emphasis mine)
Well, when you live that long I guess you get a little dysfunction, no matter how powerful you are...

Indeed... Age does have an effect. But they have pills for that.

Underworld and Corporate Download apparently have some fleeting references as well:

http://shadowrun.wikia.com/wiki/Tir_Na_nOg

There was a game here on DS a few years ago called Hitting Bottom that had two characters from there, and a long section near the beginning of the thread takes place there.
It is in no way canon, but most references to people and things were culled from the available source material.
If you are really really really interested in that land, you could give it a quick scan just for one group of players' flavor.

Thanks everyone for the book references. I have also visited the wikis (even translated the german one which was interesting).

Not sure if this counts:
http://www.tgdmb.com/viewtopic.php?t=55019