So I've read a bunch of posts regarding many different ways to configure the USPS module to do what you want, but none of them seem to answer my question. I have some items in my store that are books, and can be shipped flat rate, others that are too large and must be shipped via a small, medium or large box. How can I configure the module the provide accurate shipping quotes on checkout? I already have the USPS API configured on my site and it seems to be working, but it is still offering me every shipping option regardless of the configuration of shippable items I check out with. I've tried configuring a workflow-ng for specific flat rate shipping quotes (http://www.ubercart.org/docs/user/310/flatrate_shipping_quote) without much luck. It would seem that doing this bypasses all of the benefits of using the USPS module in the first place as you have to specify everything anyway. I've considered making product shipping classes (http://www.ubercart.org/docs/user/3341/understanding_product_classes) but these also seem to rely on the flat rate method of shipping, and besides, I can't figure out how to apply these to my already existing catalog.

So far my ubercart experience has been great, and this is the last hurdle I have before I can go live with my site. Is there a "USPS/Shipping Module 101" out there some where for people like me? It seems like a lot of people are asking similar questions, but I can't seem to graze an answer that points me in the right direction. Basically, I just want to know how to have the shipping quote (and appropriate options) be accurate to what the customers are actually buying . . . how do I make is so that "Flat Rate" isn't an option for items that won't fit in a flat rate box etc...

It seems the documentation is slim in this regard (or maybe I missed some crucial information somewhere), so I am throwing it out there to the Ubercart community for help!

Thank you for your help.

Dave