How to discount a certain product by a specific amount?

I'm using the Ubercart Discount Coupons with Ubercart 3.x and need to establish a coupon that will discount a set of books from $149.00 to $120.00, offer free shipping and charge no tax. (I don't think Ubercart Discount Coupons allows set prices yet, so I'm trying to use rules)

I have set up rules to trigger free shipping and no tax when the coupon is applied, but I'm having a difficult time setting the product price to $120.00 per applicable item in cart. Which rules parameter should I be looking for? Can someone point me in the right direction?

Also, along different lines, does someone know of a good reference (book, videos series, etc...) that helps with more complex Ubercart set up, not just basic setup?

Thank you,
Joe