2 ways to sell seminars, Adwords and banner ads (either 768X90 or better 300X250) in places where your niche meets; IE forums for chiropractors etc.
Also, either sell them cheap or free. The money is in the back-end products.
You may want to start with webinars. People don't have to drive there or fly, get a room etc. It is easy to do one. You can even prerecord one and have it set to play at certain times so that it can be used over again. (For desktop recording, Camstudio 2.1 is free and works very well. Fred Glick recommends Flip for video, but I like the Canon FS10-11, it is cheap now because they just came out with it's replacement so can be had under $350 USD. (Make sure whatever you get has jiggle adjustment built-in). The real secret to video is lighting. it generally takes 3 to eliminate shadows, but can be done with two very well placed ones if it just one person is being taped.
These seminars can also be now sold as a product! Later when you make more, the older ones can be throw-ins when selling the newer ones. For GREAT off-line info see
Maria Gudelis as she is pretty good at that niche and her mind-mapping is excellent and allows you to A) professionally sell a presentation and B) easily up-sell the service.