Will you actually be printing this/assembling it yourself? I work for a printing company and we usually outsource this type of work because it requires such a specialized process (in fact there are several types of lenticular).
If this is something you will be designing, but having someone else produce, my best advice would be to find a production vendor who specializes in the exact effect you're looking for. They would be able to give you the best specifics on how to set up the files and how to avoid any issues in the design. (For example, the last time I had to design a lenticular all I had to do was create the two separate images and the production vendor used their own program to stitch the images together.)
If you are printing/assembling yourself I have a few tips, but it may be lengthy and would depend on the actual effect you're trying to achieve.
Do you have the images already? Or are you thinking of doing 3D rendering to create them?
As far as image prep goes, isn't it just a matter of interleaving columns of information from two different images? Seems like one should be able to make a mask that would help with that, but it's not like you're making this stuff up from scratch, right? Where are you thinking of having it printed? Don't they have instructions or maybe even software to do the job for you? I can't imagine such a place would stay in business long if they didn't facilitate people's preparation of the imagery. I should think they would just require the two (or multiple) images that are going into the thing.