All of these answers are dependent on the analogy that you have chosen for your project, but here are some guidelines:
Chloroplast = a kitchen or some sort of food provider...it makes food for the cell. If you are really creative, you can add some sort of "solar power" to it to "capture sun's energy."
Vacuole = any sort of storage vat. This depends on your overall analogy--for instance, a pantry.
Nucleolus = involved in the creation of ribosomes...therefore something that would "hire" a ribosome which then goes out to produce protein.
Cytoskeleton = gives support to the cell and also provides a method of transport for organelles to get to other areas of the cell. Example: a "ski lift" if you were doing a ski mountain. Break that analogy into parts to get specific about microtubules and microfilaments.
Nuclear membrane = the "walls" around the nucleus.