Tin Whistle Tutorials
Geraldine Cotter, Traditional Irish Tin Whistle Tutor

This was the tutor that I used when I started the whistle.  Her book begins with a basic tutorial that covers breathing, how to read music, fingering, and ornamentation.  The book then includes the music to about 100 Irish whistle tunes.  I found it to be very helpful, especially with the accompanying CDs.  She has recorded one CD to accompany the lesson plans in the Tutor, and two CDs where she plays the 100 tunes so you can listen to how she plays them and then give them a try yourself.  I progressed quickly with this tutorial, but that may be in part because I studied French Horn as a child and had some prior familiarity with reading music and breathing, etc.  Anyway, this tutorial worked for me, and it probably would work for you.  In all honesty, though, some of the discussions of ornamentation on Brother Steve's page and on the Chiffboard helped me with the mechanics of ornamentation better than the coverage in this tutorial.