I'm no expert on resumes, but I would recommend checking out Anna Ivey's "The Ivey Guide to Law School Admissions." While I didn't find the samples in the back of the book to be very helpful, the chapter within the book itself is extremely thorough -- from big picture ideas about making sure it's balanced to minutiae like that you should call attention to classes you took that were outside of your comfort zone and concrete ways you can blend quality and quantity in your descriptions of employment/leadership positions.
The $14 was definitely worth it; my copy is heavily dog-eared. But a trip to Borders/Barnes and Noble would be free and just as beneficial!
Hope this helps. Best wishes!