In a large bowl, dissolve the sugar in warm water and then stir in yeast. Allow to proof until yeast resembles a creamy foam. Read more on Proofing Yeast. Mix salt and oil into the yeast. Mix in the flour one cup at a time and knead on a lightly floured surface until smooth. Place in a well-oiled bowl and turn dough to coat. Cover with a damp cloth. Allow to rise until doubled in bulk, about 1 hour.
Punch dough down. Knead for a few minutes, and divide in half. Preheat oven to 350º F. Shape into loaves and place into two well greased 9x5 inch loaf pans. Allow to rise for approximately 30 minutes or until dough has risen 1 inch above pans.