First, you need to 'blind bake' the crust, which means baking it before pouring in the filling. That way the bottom stays crispy and delicious.
Roll the crust out and place it in the pie pan. Place a piece of waxed paper over it, then gently pour in the dried beans. Bake in preheated oven at 375° for about 15 minutes until the edges are just barely brown - no more.
Remove from oven and let stand 5 minutes. Remove the beans, then fill your pie!