This site has links to each of the JKA katas:
All Shotokan-Karate Katas
Most important are those for the Heian kata, Tekki, Bassai, Kanku, Empi and Jion because
they are the current official style of the JKA Honbu Headquarters in Tokyo.
Just go to YouTube.com and search for something like,
JKA kata Heian shodan (or Heian nidan).