You asked a question about the free or inexpensive method to get started on Bing? Are you asking for training material on the use of Bing?
This is a rather simple interface and very similar in nature to Adwords. The competition is generally a little less important, but for the return on investment, Adwords will bring you 90% more traffic. I strongly recommend that you dedicate time and energy to the most available platform. If you have a very small advertising budget of less than $ 1,000, then Bing is not a bad way to start.
Do not hesitate to ask specific questions to Bing and I will probably be able to answer them for you.