Secular Charlotte Mason

Pronunciation...depends.  Truth is we often don't know how many languages were pronounced in the first place; what we do have are the educated guesses of any number of experts.  (Classical vs. ecclesiastical Latin, anyone?)  So if all else fails I just go with standard English pronunciation rules since that's our primary language and the language most of our material was written in.

Secondly, Kidipede often has pronunciation guides in their entries for difficult names.  That site is run by one of my professors; she's an archaeologist with degrees from Cornell and U of Michigan (a big archaeology school, believe it or not) and she knows her stuff.  Excellent resource; I can't recommend it enough. 

I also look for online grammar and pronunciation guides for the language in question; and if all else fails, there's always a professor at a local college, either in history or classics, or languages.  Many of them will respond to emails asking for general information, though not always.  But if nothing else, you might get passed off to their graduate student assistant who will come up with the information for you.

Hope that helps!