Two resources I recommend for scouting out the “good” neighborhoods and the “not as good” are:
1) ARJIS crime mapping, http://mapping.arjis.org/default.aspx
This lets you look at neighborhoods and ZIP codes, radius of a certain address, and more.
As a reference, based on FBI stats, national averages for crimes (per 100,000, not 1,000) are roughly 5 murders, 31 rapes, 450 overall violent crimes, 3,400 overall property crime (burglary, larceny, car theft and so forth). To compare the SD figures to these, just divide the SD figures by 100.