ABOUT GERMAN SPECIAL CHARACTERS

German uses all 26 letters of the Modern Roman Alphabet, and adds three modified letters: <ä>, <ö> and <ü>, in addition to the additional letter <ß> for the voiceless <s>, in cases where confusion could arise. As the letter <ß> is never used in initial position, there is no capital equivalent and it is then either replaced by <SZ> , or now more commonly by <SS>. The 2 dots over the a, o, and u are called an "Umlaut." The ß is called an "Eszett" or sharp s, pronounced "essett".
These are not just accents, but are indeed letters. German has the letter "a" and the letter "ä." These letters are pronounced as differently as "e" and "u" are pronounced in English. They are not interchangeable.
When speaking these letters (i.e. on the phone, spelling out a word), one would say: "a umlaut"    "o umlaut"    "u umlaut"    "Eszett"

ENGLISH SPELLING OF LETTERS THAT IS ACCEPTABLE IN THE GERMAN LANGUAGE:
ä = ae ö = oe ü = ue ß = ss

There are 2 ways to type these letters:

ADAPTING YOUR COMPUTER KEYBOARD
1. Left click your mouse on "Start"
2. Go to your Control Panel and left click to open
3. Double left click on Regional & Language Options
4. When the window opens you will see
     a smaller window in blue "English (United States)"
5. Left click on drop down arrow
6. Scroll down to German (Germany) and
    left click on German (Germany)
7. This will close the drop down list
8. Left click on apply at the bottom
    of the window, then left click on OK
9. Restart your computer
10. You are now ready to use the
     German keyboard by following
     the instructions below.
USING THE GERMAN KEYBOARD
You should be aware that most of the letters on the German keyboard are the same. Several letters, however, are reversed or in a different location. Therefore I recommend changing to the German keyboard only when you need to type a letter with an umlaut. (Ex. ü, ä, or ö) ß The letter to the left is substituted for the English letters ss in many cases.
If you are typing vom Riddle Hügel, when you get to the letter ü, simply press the Alt key + Shift and the Keyboard will switch to German. To type the letter ü, press [ then press the Alt key + Shift again to switch back to English.
GERMAN LETTER CONVERSION
ü = [
ä = ‘
ö = ;
ß = -
é = =, then press e
  (We do not see é much on paperwork.)

USING KEYBOARD SHORTCUTS
On a PC using Windows, the "Alt+" option offers a quick way to type special characters. Following is a chart of "Alt+0123" combinations that you can use it to type an ß, an ä, or any other special symbol.
These codes work with most fonts. Some fonts may vary. For the PC codes, always use the numeric (extended) keypad on the right of your keyboard and not the row of numbers at the top. (On a laptop you may have to use "num lock" and the special number keys.)
German
letter/symbol		 PC Code
Alt +		 Mac Code
option +
ä 0228 u, then a
ü 0252 u, then u
ö 0246 u, then o
ß (Eszett, sharp "s" ) 0223 s
We do not see any of the following much on paperwork.
Ä 0196 u, then A
é (e, acute accent) 0233 e
Ö 0214 u, then O
Ü 0220 u, then U
« (left angle quote) 0171 shift + \   (backslash)
» (right angle quote) 0187 + \   (backslash)
„Xxx... (left lower quote) 0132 shift w
“ (right quote 1)
(used by focus, Der Spiegel, etc.)		 0147 [   (left bracket)
” (right quote 2)
(same as English close quote)		 0148 shift [  (left bracket)
€ (euro symbol*) 0128*
html = &euro;		 shift 2
° (Grad / degree sign) 0176* shift 8
§ (paragraph, section-law) 0167 6
£ (pound sterling) 0163 3
Codes marked with an asterisk * may not display correctly in all browsers or with all fonts.
Some German publishers use the "left angle" quote as the close quote, and the "right angle" quote as the open quote, while others use them as shown above: «Wer weiß warum?»

These charts and more can be found here.