A large Midwest maker of consumer products thought a new solution that included document imaging, workflow and web services would be just the ticket. All the top executives signed off on it, and the IT department got busy. Many months and million of dollars later, the project was done and users wouldn't go near it. Today, the only part left of the system that is being used is the document imaging component. The rest was abandoned.
Talk to users. The bigger the project, the more important it is to keep communication lines open. The project may be done correctly, but if the users are not prepared for the change, it will fail.
Get everybody to buy in by asking them what their needs are. Have the users help spec hour the project and evaluate candidates.
Keep training. You need ongoing training, both before and after you convert to the new system.