I have seen Stirk mentioned in a post recently so I Googled it and all I got was it is an island west of Tamriel.

I am curious as to all what we know of the island

It's present on http://images.uesp.net/f/f9/Tam-Maps-West_Tamriel.jpg map, just west of Anvil. And that's pretty much all we know.

http://www.nexusmods.com/oblivion/mods/22401/?