If you go to the dliflc website, you should be able to find a program called
head start, which is offered in just about all the major languages. I've heard some of the audio doesn't really sound right, but the mandarin course is pretty decent.
I would not recommend focusing on only one language though, because you never know what's going to be available. I got Mandarin, which was my first choice, but there were people in my class who wanted other languages (Arabic, French etc) and a lot of people in other languages who told me they were jealous because they had wanted Mandarin. Familiarize yourself with everything and you'll have a good idea which languages you'd be okay with when the time comes. I'd also suggest your local library, but don't go out and buy anything (it isn't worth it).