I don't like the Pre / Post convention. One reason for this is that a plugin may require a combination of steps that are registered on the pre and post and async stages.
Similarly I typically prefer not to make plugins entity-specific. Many plugins can be written to be reusable across entities.
Overall, most names I go for are based on what the plugin does, with additional name parts for the implementation and the authoring company
Microsoft CRM MVP - http://mscrmuk.blogspot.com/ http://www.excitation.co.uk