Many organizations are helping with the disaster relief efforts in Myanmar. I list only a few below at this point.
Please come back often. This list will get longer, smarter, more informative and more user-friendly in the coming days. Meanwhile, I urge you to find a way to give to the people of Myanmar; the links below might help you do so:
Foundation Burma: Relief and rebuilding
http://www.foundationburma.org/may-cyclone-message.php
CHF International: Survivor support
http://www.chfinternational.org/content/general/detail/6541
International Medical Corps: Emergency supplies
http://www.imcworldwide.org/content/article/detail/1759/
UNICEF USA: Helping children of Myanmar
http://www.unicefusa.org/
American Red Cross: Shelter and drinking water
http://www.redcross.org/news/in/profiles/Intl_profile_MyanmarCyclone.html
Global Giving: Distributed to multiple organizations
http://www.globalgiving.com/pr/2100/proj2078a.html
Mercy Corps
http://www.mercycorps.org/topics/emergencies/2150
Suggested Google searches: "Myanmar relief", "Burma help", "Myanmar help", "Myanmar cyclone"