Magento

If you want to import large number of products from CSV file, your best first step would be to create a product or two manually and than export it. If you have trouble finding export file, try default folder: /var/export/

Ok! Now open it and see how it looks like.

The best way to import large number of products is to create similar CSV file and import it. Keep in mind that there are some default values. Default values are visible from the interface: Catalog> Attributes> Manage Attributes