One of my favorite topics to research is ReTweeting. I have several very large (millions and hundreds of millions of rows) datasets that I use to do my analysis. The results of my research with these databases are best practices, generated across many industries, timezones, account types and languages. This data is a great starting point for your experimentation.
The best data is always your data.
So I created a free tool, ReTweetLab that allows you to do the same kind of analysis that I conduct on my large datasets on your account (or any other Twitter account you want).
Via Jeff Domansky