Copy them from Task Info panel to clipboard and paste in the same place at the target map.
One way to do this is to create one topic in your source map and apply all your resources to it, then copy and paste the topic to the new map and it will add all the resources to the new map including their hours per week and hourly rate.
See also the discussion in this thread about resource pools. You can also paste a comma-delimited list of resources from Word or or any other word processing program. https://community.mindmanager.com/topic/70-resource-pool