A few posts back, I gave out a link to a free translator on the Marketplace that appears to be working. I've just been made aware of another one, available in world. Here's where to get it: http://maps.secondlife.com/secondlife//121/46/20 (Thank you, Dav2!)
This translator appears to have been made by a Japanese creator. It's very intutitive and easy to use though, so the lack of detailed English instructions should not prove to be a difficulty. It is not entirely free, but it's "donateware" and your donation can be as little as $L1. However, I suggest a more substantial donation -- working translators are very thin on the ground just now, and this is a very valuable tool.