Is the following quote, from To Kill a Mockingbird, a simile, a metaphor, or personification? "The Radley place fascinated Dill. In spite of...

Both simile and metaphor are forms of comparison. The difference between the two is that a simile explicitly uses terms of comparison such as "like" or "as," while a metaphor does not use explicit terms of comparison. Since the phase "it drew him as the moon draws water" includes the word "as," it is an example of a simile rather than a metaphor. 

Personification involves treating something that is not human as though it has human characteristics. The phrase "drawing water" suggests a person obtaining water from a well, and suggests a sense of intention and purpose. In this way, the influence of the moon's gravity on the tides is being personified to a degree, but the phrase could also suggest an impersonal process.

The most important rhetorical aspect of the quotation, though, is the way it portrays Dill as passively drawn to the Radley place, rather than actively seeking it out.