Cicero, Pro Caelio
This is not a typical speech (are there any?), but precisely because it is not, it allows the reader to see how Cicero plays with the conventions of forensic rhetoric. It also has obvious connections (precisely what, however, is not clear) with Catullus: if Lesbia is not the Clodia of Pro Caelio (Clodia Metelli), then she was her sister (Clodia Luculli). Wiseman (see on Catullus) is rightly skeptical of attempts to tie this whole group into a tidy bundle.
As you read, look at Cicero’s techniques of characterization. How does he create his portraits of Appius Claudius Caecus and Clodius? How does he use drama? Indeed, what is the relationship of the speech as a whole to Roman comedy. On that subject, there is a good book—indeed, just about the only full treatment of the speech:
K. Geffcken, Comedy in the Pro Caelio (Leiden, 1973).
For more general recent treatments of Ciceronian rhetoric, the following are very good:
J. May, Trials of Character: The Eloquence of Ciceronian Ethos (Chapel Hill, 1988)
C. Craig, Form as Argument in Cicero’s Speeches (Atlanta 1993) [see also my review in BMCR]
A. Vasaly, Representations: Images of the World in Ciceronian Oratory (Berkeley, 1993)
You can find useful bibliography on C. in general at:
www.utexas.edu/depts/classics/documents/Cic.html