Forums, Auction sites, Blogs, Articles, Blog Comments.... there is a few to get you started. Good luck!
It may not pay well right now, but the best bet for your long term success is to start your own blog/website and sell them there. It will take time to gain steady traffic, but once you do, you'll be in total control of your sales - and most importantly, you won't be paying a middle man to sell your stuff.
If your ebook has a good quality, it can be sold out in WF... make sure it's not a copy of others works... WF is a good place to sell IM products...
There are tons of places you can sell it. The issue isn't so much how to sell it but how to promote it and which place is best. I would say somewhere like WF if it's on internet marketing. You could also sell digital copies for kindle on Amazon.
The internet is a good place to start looking. Forums like this are great places to such items, you can use article marketing or blogging too.
There is plenty of sites to sell your ebooks, however you will have competition. ClickBank will allow you to sell your ebooks and the best part is other people advertise and promote your sales pages / site for you. You set the commission rate. You could sell them on ebay however you will be faced with having to force your price down because of the competition. Amazon will allow you to sell them if you have a paid membership. After reading the replies, everyone has great advice. I would probably sell them on a mixture of them. Clcikbank, blogs, amazon, etc..This will give you maximum exposure and sales.
all those site I'm going to list I made money with my ebooks Tradebit.com payloadz.com youpublish.com LULU.com
There are a variety of places where you can sell your eBooks, such as Digital Point, eBay, and NamePros.