Transitioning to ArcGIS Desktop
ESRI has assembled the resources below to aid in your transition from ArcView 3.x to ArcGIS DesktopArcView and ArcGIS Desktop extensions for ArcView.
Read the ArcUser article, Importing ArcView GIS Projects into ArcGIS, and learn how to import ArcView 3.x projects into ArcView 9.
Avenue Wraps
Avenue Wraps was written to help programmers migrate existing applicaions based on Avenue to the new ArcGIS environment. The book gives guidelines, along with numerous examples, for converting ArcView 3.x Avenue code into Microsoft's Visual Basic and ArcObjects code.
Getting to Know ArcGIS Desktop
Getting to Know ArcGIS Desktop is a self-study workbook for people who want to learn the basics of ArcView 9:x