Isn't your company taking care of German classes? Why don't you ask your boss or HR person? You can also look already for the Goethe Institute in the USA http://www.goethe.de/ins/us/lp/enindex.htm

For travel books on Germany I prefer the Lonely Planet.

Also be aware that as an American you will encounter a lot of political debates about George W. People will ask you questions how you Americans could let such a person to become president and so on. Some of the debates can get very hostile or at least can feel that way because we Germans tend to say what we mean. Don't get frustrated about it. You will get used to it.

About the IPhone. The American Iphone will work in Germany but I don't even want to know how high the ATT's roaming charges are. I have no idea if an American IPhone would work with an T-Mobile SIM-Card (T-Mobile is the exclusive distributor of the IPhone in Germany). So maybe an IPhone isn't the best idea.