search for: has_many_belong_to_mani

Hi. Please do bear with me as I am a newbie. I think I understand how to setup the relation using "has_many" with "through". What I need to know is how to insert data into the tables in the controller. For example, I have company details like name, address and country. I also have a category table like audio, video, events and lighting. Once I setup the relations, I need