I am sick of using the examples in the book. Is there an easy place to find data for which z-score/percentile/normal distribution stuff would be easy to see?
You may wish to read answers to this existing question on freely available datasets.
In general, I imagine that you'd want a dataset with some interesting metric variables. In psychology research methods classes that I've taught, we've often looked at datasets with intelligence or personality test scores.
One good website where you can find data for different disciplines.