Most any part of Germany is nice in teh mid to late spring. Bavaria can still get a little cold in early spring, and snow is not unheard of in the early spring.

I liked the Western Hesse and easter Rhineland area, from Wiesbaden west, during the spring. The weather is wonderful, and the country along the Rhine is awesome. You can take a boat trip up the river and have a great day watching the country pass by as you sip beer and munch Wurst.

Any city or town you care to visit in Germany will have a nice BierGarten, and a crap load of historical sites (that is one of the reason I love Wiesbaden is that it wasn't really bombed much during the war, so the historical sites are pretty much untouched, in many of the undusstrial centers, so much was destroyed by bombing in the war, that everything you see may look old, but is actually no more than fifty years old).

When dealing with Germans, they will most often speak english as well as you, but getting them to speak is is not always easy, you must make an effort to learn a few phrases, or you will likely be treated with dislike and contempt by most Germans, I am not trying to make Germans sound mean or rude, that is just the way it is (how do you feel about people asking you for directions in foreign languages?). Also, bear in mind that even if you know how to ask "wo ist die bahnhoff" in German you are likely to be answered in german, and not nice easy to follow slow German like on the tapes.

When visiting Germany it also helps to pack light and pick up a few sets of clothes after you get there, the styles are not that much different than what you are used to, but it is very easy to spot an American a mile away based on thier clothes, plus Germans are kind of funny, they will be much more comfortable with a person who has taken the effort to try and blend in, rather than stick out like a sore thumb and not care. Also remeber that the weather will be cooler than you are used to in TX, hell there summers are no hotter than a warm winter day in parts of TX, so you will not be uncomfortable in long pants and a buttondown shirt. Also keep in mind that Germans are very fussy about cleanliness and order, it is not acceptable to throw any kind of trash on the ground, not even the wrapper from a straw.

Eating in Germany is a treat anywhere you go, most restaurants have a menu with pricing outside of the front door, so it is fairly easy to decide whether or not you want to go to a restaurant. At fast food places (like KFC or whatever) it is not unusual to be served your food on real plates, they take thier chow pretty seriously, and they enjoy nice long leisurely meals, and an adult who does not have two or three beers with supper is considered odd (and no matter what you have been told belching loudly at the table is not a compliment to the chef, it is rude).