1. Word doesn't really work very well putting a bunch of documents together. It can be made to work, though. (It works much more easily if you plan on this ahead of time.)
2. You need a separate section for each part where you want page numbering to restart.
3. Then you should restart numbering on each page you want to be page 1. Insert > Page Number > Format Page Numbers
4. You can have the same footer throughout, if you want. Sections / Headers and Footers in Microsoft Word 2007-2013
5. You can use the StyleRef Field to change the footer to reflect the contents of each section.
6. You would want to change the NUMPAGES field to a SECTIONPAGES field. To do this, go into the footer and press Alt+F9 to reveal field codes. Then change the code. Press Alt+F9 again to toggle the codes back to hidden.

Note: in some instances the SectionPages field will not work if you have multiple Word sections in a logical section. If that is the case, write back and I will tell you how to handle it. Here is a hint: How to control the page numbering in a Word document