One of the most convenient things about PDF is its ability to combine files from different source programs such as Word and Excel into combined documents for emailing, filing or archival purposes. What's more, the source documents don't even need to be converted into PDF before being merged. Supported file types will automatically be converted during the merging process.
Here's how to do it:
Open Adobe Acrobat.
Choose File > Create PDF > From Multiple Files.
Choose File > Save As in order to save the resulting PDF document.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.