The following books offer introductions to the field.
Empirical legal studies articles can appear in general law reviews. They can also be found in journals for political science, sociology, or other disciplines.
The following are journals that concentrate on empirical legal studies. If you're curious, browsing recent issues of these journals will give you a good flavor of the field.
SSRN's Legal Scholarship Network includes Experimental & Empirical Studies eJournals. You can browse the combined collections, or choose a smaller collection:
Tracey E. George, An Empirical Study of Empirical Legal Scholarship: The Top Law Schools, 81 Ind. L.J. 141 (2006), [HeinOnline]
Gregory Mitchell, Empirical Legal Scholarship as Scientific Dialogue, 83 N.C. L. Rev. 167 (2004), [HeinOnline]