True that! While there is a plethora of info available, I've run into several small independents who simply do not understand small business retirement plans, e.g. SEP IRA, Simple IRA, self-employed 401(k), etc. Each has different advantages depending upon how your business is structured.
Another might be how to self-incorporate as an LLC in a particular state. While there is a lot of information on the advantages of doing so, I've seen very little about how to actually go about doing it (besides call my law firm & I'll take care of it for a modest fee).
Insurance requirements and recommendations might be another.
The importance of having a web page that drives traffic to your business.
However, while the interweb is full of info on these topics, if you are looking for something unique, I'm dead out of fresh ideas.