When scanning documents for inclusion on the website, remember you can create multiple page PDFs with your scanner. The exact details of how to do this will differ between manufacturers and even models so I won't cover it here, however, the principles are the same.
With an Epson scanner, for example, when you press the scan button you are given a box where you can change certain properties. If you choose PDF and press the scan button it will scan the first page as normal. When finished, however, you will get a dialogue box up giving you three options; Add Page, Edit Page or Save Page.
Add Page will then allow you to add an extra page to the current scan.
Edit Page allows you to edit the pages, change their order for example.
Save Page will finish the document and allow you to scan a new file entirely.
So you would use Add Page until you have all of your pages in the file, Edit Page if you need to re-order anything and Save Page to commit the changes.
Also do remember to give the file a clear name and not something like scan001 as this will be confusing when you come back to the file in the future.