Hi Chuck....
Some while ago, I made some changes to the DNN store to enable download functionality. After much coding i deployed the live site and found that the paypal gateway would only work once, (for goodness knows what reason?) Right there, i had no time to unpick the paypal gateway so i went with a different ecommerce store....
However if you want to get coding in the store you need to (as i remember) ... open the store zip that contains (suffixed with .resource i think) Then opnn that up as a Visual Studio project. You may have seen in previous replys exactly what to do. I remember i made the same mistake and opened the DNN project rather than the Store project.
Somehow Giles / The DNN team linked these projects together so that the store .dll's get copied over to the DNN project each time you rebuild the project. Then, if you are developing locally, you can go to your browser - do a refresh and then the changes become apparent in you DNN project. - Brilliant.
Don't let me confuse you, you'll see it all once you open the project from Store.sln (or what ever the exact file name is)
I see you are quite new on the forum, without wishing to detract from the excellent work the DNN team have done with the store - Can i HIGHLY recommend that you take a look at NB_Store - It has ongoing development by a dedicated team and is the only store i use for clients shops now.
Download from here http://nbstore.codeplex.com
I believe you will be pleasantly suprised :)
Reply to this forum if i can help you any further... if its about NB_Store then we better take it to another thread.