When you are adding views to sheets, it can take Revit a long time to regenerate the views once they have been placed. Multiply this for an entire project and adding views to sheets can be a very time consuming process.
If you are going to be creating a few sheets, try closing all the Worksets and then add the views. With nothing visible in the views this will dramatically speed up the process.
If you are using the Grids or Levels to line up the views on the sheets, then you can have the ‘Shared Levels and Grids’ Workset open.