You need to insert an image plane... its quite simple and only takes a few clicks.

-First make sure your reference images are all to scale.

-Then in the corresponding view (so side image go to the right view) go to View > Image Plane > Import Image

-Then move the image plane so they are all level and then push them out so they arn't in the way in your perspective view.

-If you want them completely removed from the perspective view select the image plane and then under the image plane attributes change the Display to Looking Through Camera.


Hope that helps!

T