canton fair 2013 invitation

I recently retired from banking here in Nigeria, I want to start imports of building materials as I want to venture into real estate. I want to visit the next canton fair in april 2013 to make some contacts and also make some orders, however am new to this as i have no contact in china to give me the invitation to apply for the visa. kindly help me with the process of applying for invitation to canton fair as an induvidual. and also for the visa and the appropriate time to apply