It looks like your instructions did not get uploaded. I'm not sure that I will be able to offer much assistance but I will definitely take a look and see if I can make any suggestions.
Adding in the length, width, and height will be a little more involved. You would need to start with modifying your products table to include the columns for these values. Once you have done that you will need to make use of DataAssist to update the admin pages for inserting and updating products. You will need to add in form fields to collect this info and update it.
Once you have done all of that you will then need to modify your cart object to have these columns. Finally you will need to update the product details page to edit the add to cart on this page and associate the new columns with values from the rs.
This is a bit of work but it is something that can be done, it will just take a little bit of effort to get it in place. Once you have the values in the cart you could then make use of them in your shipping quote code.
