Nope :) As far as I'm aware the "scharfes S" is slowly becoming extinct. Fingers crossed that the umlauts follow eh? :p.
Weiß is a good example of that, with Weiss being used more and more frequently (probably because of us auslanders ;p). However, bear in mind that "weis" doesn't mean "white".
"meine" is feminine and plural. "mein" is masculine - it's a der, die, das thing. "Hemden" is plural (shirts) so we need to decline the article (Verbs are conjugated; nouns and adjectives are declined).
Once you've got the bit worked out (which I think I have) you then need to work out which case (accusative, nominative, genitive, dative) as that also influences the declination....
German...it's fun...so I'm told ;p