Perform the desired action using the menus bar items. The menus will list keyboard shortcuts that exist.

For example, in order to find the keystroke to save a record, click File on the menu bar. Next to the action, Save, is the keystroke shortcut Ctrl+S. Use this keystroke to save the record without having to use the mouse.
Review The Raiser's Edge 7 Batch Quick Reference, which includes a list of shortcuts.