Hi
Cromertech and Domino answers are both right - it all depends on whether you want the logo to appear in the exact same position on every page - in which case you need to ask to create a custom header (INSERT - HEADER - EDIT HEADER) and drag your logo to anywhere on the page (this does not have to be within the header/footer margins).
Double-click anywhere outside of the header/footer area to return to your document text. If you add new pages (CTRL+ENTER) you will see the logo appears on every new page in that position (along with any other header/footer text).
You can also, use this method if you only want the logos on the first page: simply click the "Different First Page" option on the Header and Footer Design Tools ribbon tab and then use the "Next/Previous" buttons to set the First Page Header/Footer details then click "Next/Previous" again to move onto the Header/Footer to set the Header/Footer for the rest of the document (in a similar way to setting different headers/footers for sections within a document).
The other method of setting logos on only one page in a document is to change the Text wrap on your logo. When you click on a picture, the "Picture Tools-Format" tab is added to the ribbon (last tab on the right). Making sure the logo is still selected, click the "Wrap Text" icon drop arrow to see the choices and set it to something like "Top and Bottom" (no text beside logo allowed) or "Square" (text allowed either side but wrap doesn't make sense unless logo is at left/right margin or you have columns set). Now you need to stop your picture moving whenever you move/add text above it: with the logo still selected, click on the "Postion" icon, then "More Layout options..." and on the "Position" tab in this dialog box, untick the "move with text" option at the btm left of this dialog box and click OK.
You may find a helpful manual section from this website which does publish some free courseware downloads: wiseowl.co.uk/courseware/word/index.htm
I hope this is helpful.
Penelope
