Plea for sales advice

Can anyone help a friendly geek attempting to learn the mystic hidden art that is sales?

I am in the process of putting together a company to provide ASP.Net training in Leeds. The only thing I am lacking is sales!

Can anyone out there advise me on the best approach to take, help or books on writing sales copy, where/if/how to advertise..?

From what I gather if I get this stuff wrong I could do more harm than good so I am hoping to get it right from the start! smile

Cheers

Chris