Is visa to Hong Kong and Macau necessary or there is provision of on-arrival visa for me?

I have an academic conference at Macau in June 2013 and I want to visit some places at Macau and make a trip to Hong Kong for a period that would not exceed 12 days. Please advise what should I do to get my vis if necessary and if not what would be the procedure for entry into Macau and thereafter to Hong Kong?
Dr. Rajib Handique,
Associate Professor,
Department of History,
Dibrugarh University,
Assam. PIN 786004.