Yeah, talk about the formation of the Delian League, but mention points like when Athens first began to intervene in her allies affairs, and how she made then sign oaths later on.
Personally, I'd end it with when the Delian League was finally seen as the Athenian Empire- around the time they moved the treasury from the island of Delos to Athens. You also might want to mention the use of the tributes in Perikles building program- there are some good quotes from Plutarch about Perikles justification for this.
But include examples of when Athens began to turn revolting allies into colonies and stuff like that, too.