These are the links that were used for demonstration at the 12 April 2012 FTM & CG SIG meeting. If you are new to DNA for genealogy, I recommend checking out the last three links first then the FAQ and Glossary links for more details. The last link is to a video with Spencer Wells who explains how DNA testing has evolved and is being used for genealogical purposes is probably the best place to start for background if you have 20 minutes to devote to it. Note that some of these links require a login or ID to access fully.
Family Tree DNA: http://www.familytreedna.com/
MyFTDNA Home page: https://my.familytreedna.com/default.aspx?
FAQ's: https://www.familytreedna.com/faq/answers.aspx?id=17#626
Glossary: http://www.familytreedna.com/faq/answers.aspx?id=21#781
Interpreting Results: http://www.familytreedna.com/pdf-docs/Interpreting-Genetic-Genealogy-
Results_web_optimized.pdf
Ancestry.com
DNA Home page:
http://dna.ancestry.com/viewConsole.aspx;jsessionid=DF804F8021DB85F35AD83F10142CFE02.dna03
Matches: http://dna.ancestry.com/compareY.aspx?uid=2607344&tid=129549
FAQ's: http://dna.ancestry.com/faq.aspx#testingRightForMe
23andMe: https://www.23andme.com/
ySearch: http://www.ysearch.org/
MitoSearch: http://www.mitosearch.org/
Gedmatch: http://gedmatch.com/
Other DNA Resources
Use of DNA Results Explanation: http://blairdna.com/dna101.html
Kerchner's DNA Testing & Genetic Genealogy Info and Resources Page: http://www.kerchner.com/dnainformation.htm
Spencer Wells builds a family tree for humanity:
http://www.ted.com/talks/lang/en/spencer_wells_is_building_a_family_tree_for_all_humanity.html