Moving objects between containers in AD.

Can anyone provide any input for a newbie-with-little-idea-about-AD? We have a Win2003 functional level domain. There are 2 OUs “A” and “B”, both with 5 sub OUs – Computers, Groups, Resources, Servers, Users. If I am to move all the objects in the 5 containers from “B” to “A” (so that B is then afterwards deleted), what preparatory work if any, would I need to do? Thanks in advance.