Can you give me an example of an organelle analogy? I can't use a school or a city. Please give me ideas.

Shoot!  No school or city.  Those were actually going to be my first two suggestions.
 Don't worry though.  I have a few more.  

You could use a corporation.  The
nucleus would be the CEO's office.  That would make his office walls the nuclear membrane.  The
mail room and delivery guys could be the endoplasmic reticulum....