Concrete Noun: a person, place, or thing that can be perceived by the senses (can see it, hear, it, smell it, feel it, or taste it); concrete nouns are tangible.
Examples: orange, ball, girl, John
Examples: love, beauty, bravey, capitalism
The Abstract Noun - one page html poster had a neat visual and textual mini tutorial explanation and examples of presenting this concept. (Chomp Chomp.com)
Abstract Noun Worksheet - suitable for younger students; from Home Schooling Haven.com
List of sample Abstract Nouns and Abstract Noun worksheets (Free Teacher Worksheets.com)
Abstract/Concrete Noun Drag and Drop Sort from EZSchool.com
Abstract vs. Concrete Nouns Drag and Drop Sort from Mr. Nussbaum.com