I am starting on a silverlight application and my MainPage is getting to be fairly large. I am not sure how to properly make a silverlight app in terms of object orientation or separating things into multiple xaml pages. Is it normal to have all of your application in the MainPage? For large elements such as a drawing tool, do people make custom controls and then add them in the main page?
I’m not really sure how to set this up and was hoping someone would shed some light on what the normal architecture of a silverlight app is.
As Steve B suggested you should look into MVVM and use that basic pattern to separate your application into views, models and view-models which bridge the gap between the view and the underlying models. The pattern is not difficult and works very well for data binding in WPF and SilverLight.
To manage the complexity of your main page use multiple UserControls to keep different parts of the UI in different files.