Shipping - Free & Flat Rate

Some products are free shipping, the rest are flat rate shipping. The ebooks are free shipping, everything else, no matter how many products a person purchases, is only $12 flat rate per order. How can I accomplish this without charging $12 per product??

It's really easy. Just don't set a weight for your ebooks and set a weight for the others. Then, in the menu System->Shipping methods, click on "manual shipping methods plugin" and create a new shipping method and set your flat rate in the "price" field and save. Voilà.