It's really quite simple to insert a page # field by:
1. going into the header/footer;
2. positioning the insertion point where you want the # to appear;
3. pressing Ctrl-F9 to create a pair of field braces (i.e. { });
4. typing 'PAGE' between the field braces, so you end up with {PAGE}
5. pressing F9 to update the field.


If you want to control the format of the field, either:
A. apply a suitable Style to it or its paragraph; or
B. at Step 4 above, type 'PAGE \* MERGEFORMAT' between the field braces, so you end up with {PAGE \* MERGEFORMAT}, then format the 'P' of 'PAGE' with the desired font attributes.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]