Hey Pammy,,If you are going to sell ebooks, you need to either have an ebay store or your own website, or at the very least a hosting site where your customers and go and download their ebooks..
As far as the ads,,you might try looking at the completed listings on ebay and see which sellers are successful and then look at their ads..Then don't copy it, but try to use the same format,,that is same size fonts, colors and pitch..just make it your own version...
In additional it's hard to sell the same ebooks that everyone else is selling or that are just out of date...What you ideally need to do is to create your own ebook on subjects that you are familiar with..Just about any type of ebook can be sucessful in any catagory..You just have to market it and make it available..One of the best ways to do this is to find a subject that is pretty popular and offer that product as an enticely low price..Just enough to cover your fees..then when you make sales on those books, capture their email address and make additional book offers to your email list..Also think about offering a free newsletter and then you can also offer to that list as well..Use your 'about me' page to offer your newsletter and also when you do sell a book make sure that you send an email 'order received' or thank you notice and include a link pointing to your store and or website....
If you don't have much writing skills, then buy a software that will write the ebooks for you,,such as 'instant article wizard' these programs will pretty much do the book for you in just a few minutes on any subject you type in the box...
Too you might want to align yourself with some of the more successful writers and sellers that have affiliate programs, and just sell their stuff and get a percentage of the profits from their books that you sell or the traffic that you send to their site buys...