I have a large blender file.
How can I compress this file and can I split the file into multiple files to ship it?
All you need to do is check the Compress File box when saving. If your file is still too big, consider using a service like Dropbox or YouSendIt.
If the file is made of a bunch of scenes you can import them into separate .blend files. To append a scene from a different file use File > Append
. Find the file and click on it. Once you do, you should see a bunch of folders. Select the scene folder. Click on the scene you want and open it.
You can then proceed to save off each individual scene into a separate .blend file.
One other possible reason that you have a very large file is because of cached simulations/animations. If you are trying to send a directory with a bunch of sim caches, I would recommend deleting those. You can always bake them later after they're sent.