Help: How do I have a drop-down cell auto-populate other cells based on result?

Hi all,

Summary
I work in a customer service environment and we're adding upselling into the mix, but I need a sheet that the guys can fill in quickly to track their commissions. Ideally the fewer cells needing population the better as filling the end product with some degree of speed will be necessary.

Detail
I have a list of products, each one corresponds to a commission value. I want to have the products in a drop-down (already done) and to have that selection populate another column with pre-determined commission amount (not done), which will then be totalled elsewhere.

In addition to that, I want another drop down (Yes/no) to qualify whether the figures are entered at all. I.e., if this cell is no, commission = 0. If this cell is yes, read and populate the commission from a table.

I've uploaded what I cobbled together so far - I haven't used Excel beyond the most basic level in a VERY long time, so hats off to you experts; I forgot how in depth these things can go.

Any help would be greatly appreciated.