This is some thing that came to my notice in all rotoscope tutorials that use more than one image to make a 3d object.
1) When setting up more than one rotoscope from the same blue print picture don't split the image up into front, side, top and back. I will come to the reason in a moment.
2) Keep whatever images you are using the same size. If you find it easier you can blank out the sides you don't need for each view. I Used PaintShop to make the background colour transparent and to remove parts of an image I wasn't going to use for a particular side. With the top view image you most probably need to rotate it to face the same way as the side rotoscope.
(don't attempt to use the manipulator as it dose not show you the scale percentage when you try and change its size) and you can take forever trying to match the 2 images.
3) The reason for using the same size image is that When you put the rotoscopes into the model it is possible to get all the images the same size. this is done best by changing the Scale value of the rotoscopes. The X and Y value should all be made the same value for all the rotoscopes you use for the model. Once you have done that all you need to do is line up the 2 or 3 rotoscopes.
4) In the front view I made a 2 Cp spline from the very top of the front rotoscope( i.e. top of human head to chin) to its very bottom. I used this spline to measure up the side view.
If you going to use a top rotoscope then make another 2 Cp spline in the front view that is the width of the face. This line will help match up the top rotoscope width.
5) Once you have matched you rotoscopes remember to set them to be "unpick able" so they don't move once you get going. Delete the Cp's that you used as reference if your happy with the match.

Will I think I have done a fair bit of hard work there. It would be nice to have some else show me how to get the splines to spread evenly as I model away. Just a few simple tips please then I guess I can get on and finish this tutorial condense it and make it into some easy steps to follow

This really helps, thx!

Good tips. I sometimes have trouble with rotoscopes

What I've been doing is creating them all in the same Photoshop file in layers. That way I can line them up on top of each other (by temporarily adjusting the layer's opacity). Then I just turn on the layers I want to export and do a "save as" to a Targa file. The beauty bit is that Photoshop won't let you save the multi-layered document as a Targa, so it saves a copy. That way you can keep the file open as you export your various rotoscope views and not have to keep reopening the file.

Since every file you save is coming from the same file, they are exactly the same size.