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).
Thanks to Jeff Domansky for pointing out this great analytics tool. It provides interesting insights into how, why and when your tweets are retweeted. Best of all: it's free!