There are numerous eBay courses that are attainable on the Internet today. These books & courses are designed to help you become more successful on eBay. Unfortunately, not all of these courses are worth the money that you will pay for them. Some of them are full of what used to be good information - when it was relevant - and others are simply junk information, written by someone trying to make a quick buck.
Before you buy any eBay course, find out when the course was written. If it was written in 2004, for instance, you don't want it. Even though that hasn't been very long ago, eBay changes so fast that much of the information will not be relevant. However, if the original issue of the course was written several years ago, but the course is updated each year, this will probably be a good course for you.
Again, use care when purchasing eBay courses. They can be quite helpful and enlightening, but only if the information in them is still good. Talk to other eBay sellers - preferably successful ones - to find out what courses are recommended.