Let the yeast do it's thing. While that's happening, get these things together:
Mix the sugar, butter, salt and egg in lukewarm milk. Add yeast mixture and stir, working in the flour until dough is dry enough to knead. Knead until dough is smooth (about 10 minutes).
Put in a large greased bowl and let rise 2 hours or until double. Punch down and knead again. Divide in 2; put into loaf pans and let stand for 1 1/2 hour or until doubled. Bake at 350 for 40 minutes.