What is the best, free or cheapest way to import 1000's of products, images and cvs files?
NopCommerce does have import features. You can import around 500-1000 products at once using the import feature of NopCommerce which is available at the product listing page in the admin section.
I exported from nopcommerce, added some items in excel and now get this message.
The file is not an valid Package file. If the file is encrypted, please supply the password in the constructor.
I managed to do it from a new version of excel, but can I leave some cells blank?
Yes, it's not mandatory to have all cells filled. Be sure you provide product name, price, and SKU if available.
All Images just stay on my server in a folder for the nopcommerce site to point to I guess also?