Inserting scanned pictures into word files

[Rosie173]

Can anyone suggest what I must do to get good quality images that are not enormous, from scanned photos which are jpegs, into my word files?

I am trying to put 450 A4 pages of a family history into MS Word on computer. The text is already in MS word but there are hundreds of full sized photos often 4 overlapping per page which i am scanning in and placing among the text. The work has been done by someone else who is not familiar with digital images.
So far the book has been printed from hard copies of printed sheets and the photos are just glued on pages which makes it hard to print and difficult to update and change the book.

After much ado I have divided the text into blocks of 24 pages per file and am inserting the pictures this way so that each file doesn't get too big but what is driving me absolutely crazy is understanding how the images work when they are placed in word

I can copy part of a picture of 618kb, paste it into the word file and the word file size will go up by 4 megabytes.

I have tried reducing the original picture file by using grayscale, altering the size of the picture in photoshop, altering the resolution but it is all hit and miss and I am not sure what is really happening. I want reasonably good reproduction in the document but I just don't have the skills to cope with all this. Please, please help.