I think that the following steps are the best way to get blueprints aligned:-
1. Make sure you have found accurate blueprints.
2. Use a program like photoshop to cut out each view as a separate rectangular picture.
3. Put the appropriate pictures in their respective views inside cinema 4d
4. Use a cube primitive to align blueprints.
5. Start with the side view: Use scale operation on the cube to align it perfectly to the side view
6. Go to the top view: Use scale operation on the cube again to align it perfectly to the top view.
7. Once you have done 2 views, you cannot touch the cube anymore. So now you go to the front view and scale down your picture uniformly(NOT THE CUBE). If the blueprints are perfect you will see that the image will scale down to fit the cube. At max, you may need to offset the picture by some pixels.
8. Repeat step 7 for the rear view.