If you are planning on distributing your ebook through Apple, (and don't own a Mac) as well as other ePub outlets like Sony, Diesel, Books on Board, Kobo, or other retailers that do not allow self-publishing, you'll need to use a distributor.  To save yourself some trouble, you may as well use an Apple Aggregator.  You may find a list of Approved Apple Content Aggregators at this link:  CLICK HERE.  You may research this list in order to find a distributor that meets your needs.