File> External Drawing> Place external Drawing.
If you want it to show in a floor plan window, place it there. If you just want to be able to reference it while you work, place the drawing (JPG) in a worksheet. With floor plan window active, in the navigator right-click on the worksheet and select 'show as trace reference'.
Please add your AC version and OS to your profile.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"