"Since some of the "Sites" I go to are about Satellites and are in German I come into intimate with the Letters ÄÖÜ and Firefox insists on useing the Western (8859-1)"
Changing the default character set might solve your problem, depending on the sites you usually visit, and how they were coded:
Then in "Fonts & Colors" -- sorry, mine is American :-):
Advanced...->Default character encoding
Ideally all sites would set their "charset=something" in their <head> sections and then we wouldn't have to worry... Apparently the satellite site you mention does not do that, therefore your problems. I see that frequently with sites in Portuguese too, and then have to guess which charset was used to write the page because they didn't explicitly say it in the <head>, and using UTF-8 is making things look rather weird. :-)