Here is an 8 page PDF that walks you through the steps you need to follow in order to bates-stamp a document (or documents) in Acrobat X. The PDF is made up of a series of screenshots so you can see exactly what you need to choose.
Bates-stamping in Acrobat is pretty easy once you've done it a couple of times, and it's usually a lot easier to do it yourself than to ask your paralegal. There are choices, and you should be the one to make them.