Here is a pretty good language book. It goes pretty indepth on grammar. I own this one:
http://www.chapters.indigo.ca/books/...e+book+CD+pack
Pimsleur CDs work well for fast learning of basic necessary language:
http://www.chapters.indigo.ca/books/...sleur+Croatian
If you have more time, you can order from these books. I own these ones as well:
http://www.vodnikova.hr/index.php?mod=nakladnistvo
Have a good trip, and share the details with me when you get back. I would be very interested.
And if Mango sees this thread, she might be able to help you more. She has been there before.
BTW, I heard Gornji grad in Zagreb is a must see.
Do viđenja!