I am using the framework of grails meaning I am using hibernate but I eventually plan to implement this on MySQL after a month or so. I am having a hard time designing this and it would be a great help if I could get a small help here. The diagram is provided in the file and I just need a small tweaks especially for the address of the contact. I am an enthusiast programmer trying to help my aunt in her company (to save her money) and I don't have any good programming education just used wikis and other self help websites. Thanks!

Also it would greatly help me if one would use table joins. I know it is a great concept but I really have a hard time grasping it. For example a table where it would display the contact name and the conferences that he/she will be attending.