Not the same as the other thread

Ok so I have a website ..great have learnt a little about setting up the way it runs
now I would like to know how do I go about setting up up products from a csv file... I will be getting a csv file from my supplier but I will need to add my own percentage and upload to my site or vice versa
How do I go about this as I can't seem to find any explanation as to if it can be done or how .
Is it possible I can find presat shop stuff but I am running zencart and then there is easy populate which seems a little beyond my scope
Hope someone can help
