You can distribute the GroupWise client to your users' desktops in a variety of ways, as described in "Distributing the GroupWise Client" in "Client" in the GroupWise 6.5 Administration Guide.
You should also distribute the GroupWise Import Utility for Microsoft Outlook to your users so that they can import their Outlook PST files into their GroupWise mailboxes. Depending on the needs of your users, you could provide a network installation of the Import Utility that users could run, you could e-mail the Import Utility to users so they can install it on their own workstations, or you could provide them with the URL for the Novell Downloads page where they can download the Import Utility for themselves.
Also, let users of public folders know that they will receive notifications that they must accept in order to continue participating in the corresponding GroupWise shared folders.
To help users adjust to GroupWise, make sure that they have access to the GroupWise Import Utility for Microsoft Outlook Quick Start (ImportUtilityQuickStart.pdf). It is available in the installation directories of both the Migration Utility and the Import Utility. You might want to print copies for your users to help them get comfortable in their GroupWise mailboxes as quickly as possible. For your convenience, the same information is presented in Using the GroupWise Import Utility 2.1 for Microsoft Outlook in this guide.