I prefer to use an US keyboard as most programs are optimized for this keyboard layout and quite a number of characters are hard to reach on the standard German keyboard layout (or even the Swiss-German one, argl).

Still sometimes it might be nice to directly input German Umlauts into the text. The normal US layout offers these keys using combinations of AltGr and some non-easy to remember key. Or you can use the US International layout (us_intl), but then the quotation mark become dead keys (not very nice).

My keyboard layout makes it easy to type the German Umlauts. Download the keyboard description and copy the file below into the directory /usr/share/X11/xkb/symbols as us_de (this is under Debian, your Linux distribution might have the keymap files somewhere else). Then you can directly use setxkbmap us_de to load the keyboard set. It is also possible to enter french accents using dead-keys.

# cp us_de /usr/share/X11/xkb/symbols
# setxkbmap us_de

To make the changes permanent, you have to change the keyboard section in your XF86Config.

The following key-combinations have been defined:

AltGr-a               ä
AltGr-A               Ä
AltGr-o               ö
AltGr-O               Ö
AltGr-u               ü
AltGr-U               Ü
AltGr-s               ß

AltGr-~               Dead Version of ~
AltGr-'               Dead Version of '
AltGr-^               Dead Version of ^
AltGr-`               Dead Version of `