I studied German at the Goethe Institute. See
http://www.goethe.de/ins/us/enindex.htm/ for a list of U.S. locations. They have locations worldwide. This is from 25 years ago in London, but the instructors were first-rate, and the cost was low. I took two months full-time and it was enough to get me started in Germany where I was working. During the training, I started getting headaches as my brain rewired, and I couldn't speak English or German properly for awhile. I took advanced German in Abendschule for a couple of years and passed the German language entrance exam at the Free University. Here's a tip - when you're memorizing nouns, always learn the gender of the noun. When you get to Germany, speak as little English as possible for awhile. Since so many people speak decent English, it's tempting not to make the effort to speak German. Start reading challenging publications like Der Spiegel. This will also get you up to speed on what's going on in Germany which will impress your German contacts. Good luck!
Tom