In this video, I'll make a very simple house in Google Sketchup and then importing the model into Moviestorm via the Modders Workshop.
This is still quite a straight forward process, and can be attempted even if you are relatively new to Moviestorm. Obviously, we can't offer advice on how to model your own content in Google Sketchup, but this tutorial should give you an idea of the conversion process required to use your models in Moviestorm.
A few things you should bear in mind when creating assets in this way.
Keep your polycount as low as possible - Sketchup models can quickly become quite complicated and computationally "heavy" to manipulate in real-time. It is very important that you create your assets with this in mind, otherwise you may find that your models quickly bring Moviestorm to a standstill.
Keep your naming convensions simple and accurate - it is very easy to lose track of assets that you have created so a concise naming system will help you to identify your assets quickly and easily.