Hey guys-
I'm just not getting this shipping stuff. Can someone give me a simple 'how to for dummies' version?

All I need is for orders total from $1 to $39, shipping is $4.95 via USPS. From $40 to $99, shipping is $9.95 via USPS. Above $100, it's free.

I THINK I have the Free Shipping piece setup (thanks for the tutorials section). But the other part I'm not figuring out. Any pointers for me?

Thanks guys!