I love Apsona ShopAdmin but getting information about it and figuring this out initially can be a bit difficult. There's a lot at work here and I finally wrote up a document that explains some things that I consider important. I guess you can call this an introduction to Apsona. That is the link displayed below this description.
I am very greatful to the Apsona team for this mod and their commitment to continuing the server behind the mod. They don't provide support for the mod any longer but they are keeping the pieces in place. Thanks!
There are supporting documents on Apsona. I've never taken the time to read through all them but there is a world of information there and to start you off here's the link to the Importing Products page since this the feature I find to be the most often used.
Here's the link to the PDF.