Typically this process is done with a film camera, you expose the film twice to 2 different images.
Research Double exposures for inspiration, post your research on your blog with a paragraph description.
On a separate blog post and before beginning your artwork write up a paragraph description of what you would like to do and discuss it with the instructor. Use visuals if necessary, include them in your blog post.
Using two photos YOU take recreate the double exposure look using Photoshop.