Right click on the picture and choose "Order" then "Send to Back" (or right
click on the text and "bring to front"). This will bring the words over the
picture. Or you can insert the picture on the Master page if you want the
same picture on multiple pages.
Depending on the picture you may want to format the picture so that the
Image Control is set to Washout if it is hard to see the text over the
picture. (right click on the picture, click Format Picture and change the
Image Control Color from Automatic to Washout.
I have not seen an option to alter the transparency of a picture as you can
in other Office Programs yet...
Hope it helps!
Tanya