In a large bowl combine the yeast, sugar, and water. Let stand for 10 minutes or until foamy.
Stir in the oil and garlic salt.
Add 3 cups of flour and blend. At this point, the dough should be soft and pliable. Slowly add more flour until it is no longer sticky.
Turn dough onto a lightly floured surface and knead until smooth and elastic. Place dough in an oiled bowl and turn twice to coat. Cover bowl with a kitchen towel or plastic wrap and set in a warm place to rise for 90 minutes, or until the dough has doubled in size.
When the dough is done rising, punch down and divide into two pieces. Roll each piece into a circle and place on pizza pan. Bake at 450 degrees for 12-15 minutes.
Add pizza toppings.