I took Latin in high-school but I always wondered what Latin would have sounded like.
* descriptions of the sounds by the Roman grammarians
* wordplay, onomatopoeia, spelling errors in graffiti, etc.
* the way in which sounds from other languages (particularly Greek) were adapted into Latin
* the way in which sounds of Latin were adapted into other languages
* comparative reconstruction of the Romance languages
* evidence from metrical poetry, which provides particular clues about consonant and vowel length
A very readable book on is W. Sidney Allen's _Vox Latina_.
[edit: meant to reply to immediately following sister of this post.]
I wonder how anthropological linguists would someday treat modern rap and hip-hop. In German, for example, it's not uncommon for the artist to slightly or not-so-slightly mispronounce words to make them fit a rhyme. Would that help or hinder a study?
I imagine it would help. If evidence for that mispronunciation happened consistently, it would be taken as a dialect, class, geographical or cultural thing (or subculture). If it happened consistently over a very short space of time (and there was surviving evidence) it could be confused as a blip, or fashion.
Example:
I'm constantly perplexed why 'where' is spelt as 'were' by so many, but I imagine there are a sufficient number of English-speakers' accents (or a sufficient amount of speakers of a single accent to be significant) where the two words sound similar enough to spell them out on a keyboard as the same.
For example, I think I've seen "besino" written by a native speaker for "vecino" 'neighbor'.
The best approximation we have is what's called the "restored" pronunciation. If you're interested in all the nuances the best book for this in my opinion is Vox Latina by Allen. Alternatively, just listen to anything by Evan der Miller on his YouTube channel: http://www.youtube.com/user/evan1965. His Latin pronunciation is the restored Classical and extremely good.
If you took Latin in Highschool and want to get back into it you should check out a book course called Lingua Latina per se Illustrata. It introduces Latin through Latin and also contains MP3 recordings for the first 31 chapters in first book, all in very good restored Latin pronunciation by the author Hans Ørberg. (there's a torrent of all the Lingua Latina resources)
I am pretty sure there are no legal ebooks of familia romana, its full of illustrations and the ebook transition would likely be painful. Too bad.
Unfortunately it's quite far away from the pronunciation I've learned in school.
(and what Americans usually use seems to be even farther away)