How does the author use imagery to describe the town and what mood does this describe create?

I'm not sure how to help you mate, since you didn't include anything that had imagery or mood, but I'll try my best...
Imagery is description basically.  For example, when you're writing (or reading) you should be able to imagine exactly what is being described. ie; "Snow White's bright painted cherry lips brushed softly across the firm flesh of the apple."
Mood is how you're emotionally effected by the writing.   Music is the best example of mood.  For example, during a horror music how there will often be scary violin music?  That helps increase the mood/atomosphere or the movie.  Same thing with writing. 

I hope I helped mate, good luck!~

Yeah we could do a lot more tomorrow