As per the Uttardi Matta Panchanga, this year both the Swarna Gowri Vrata ಸ್ವರ್ಣ ಗೌರಿ ವ್ರತ and Ganesha Chaturthi ಗಣೇಶ ಚತುರ್ಥಿ festival are on the same day; i.e September 11th Saturday 2010.
Please contact your local temple for the exact day you have to perform the pooje based on your location in this world.
Details about the festival, the many stotras and slokas, stories, food items that need to be prepared are posted in great detail at the following link in this blog.
May Lord Ganesha remove all the obstacles from one and all. Jai Sri Ganesha