http://cvphysiology.com/Tutorials/Tutorial%-%20ECG.htm
Here's one. If you just google "ecg tutorial" you should find lots of resources in different formats!
Well, sorry! I can't get my links to work using this browser. Just google it, you'll find good stuff.
Plus, if you go to the critical care section of this site and click on CCU there are links under "helpful information for the unit"