Chiral Publishing
Chiral Publishing: An Introduction to Chemistry: Difunctional Organic Compounds
Investigate organic compounds that have more than one functional group using these interactive 3-D models. Also find links to animations, tutorials, and power points about other chemistry topics.
Wolfram Research
Wolfram Science World: Organic Chemistry
This site from ScienceWorld provides a brief look at some of the more common organic functional groups. The carboxylic acid group is also given. Quite a few links are provided at the bottom of the page for additional information.
Other
Introduction to Nitrogen Functional Groups
This organic chemistry tutorial describes the general class of nitrogen functional group compounds (amines and amides).
Upper Canada District School Board
Tom Stretton's Chemistry Pages: Functional Organic Groups
Through an online slide-show format, learn about functional groups in organic chemistry.
Wikimedia
Wikipedia: Functional Group
Encyclopedia entry for functional groups that, in in organic chemistry, are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.