http://kepler.nasa.gov
"NASA Kepler Mission is searching the skies for planets that are the same size as Earth--worlds that could possibly be similar to our own."  The spacecraft identifies transiting planets as it scans more than 100,000 stars near the constellation Cygnus, looking for recurring dips in the light curve.  Excellent website with many resources, including:

• Classroom Activities
  
• Formal Education, Informal Education, and Public Outreach
  
• Models and Simulations
  
• and much more.

http://planetquest.jpl.nasa.gov/
PlanetQuest Exoplanet Exploration is an engaging site for news and multimedia about NASA's search for new worlds.  Keep pace with current tally of new and candidate planets; get your questions answered by Astronomer Steve; create your planet with Extreme Makeover; check out the great videos from multiple NASA missions, and always see the latest exoplanet news at the forefront of science. 

http://kepler.nasa.gov/files/mws/TransitTracks-7-2010.pdf
Transit Tracks is an investigation in which students describe a transit and the conditions when a transit may be seen; describe how a planet’s size and distance from its star affects the behavior of transits; and interpret graphs of brightness vs time to deduce information about planet-star systems.

   http://oklo.org/
The Systemic Weblog, written by Greg Laughlin, reports recent developments in the field of extrasolar planets, with a particular focus on observational and theoretical astronomical research work.  Tutorials show how to use the Systemic Console, a program that "uses an intuitive graphical interface to analyze data in order to detect and characterize planets."

http://www.transitsearch.org/
An observing program whose purpose is "to coordinate and direct a cooperative observational effort which will allow experienced amateur astronomers and small college observatories to discover transiting extrasolar planets."  To observe transiting planets around distant stars, you need a telescope with an accurate clock drive, a CCD camera, and appropriate computer software.  Observers who obtain photometry of known transiting planets can submit their light curves.  The transitsearch.org site currently functions primarily as an ephemeris information service.

http://www.planethunters.org/
Actually find new planets orbiting distant stars using the data from the Kepler mission.  Participants steer astronomers to candidate stars by judging the existence of patterns in a light curve.  From Planet Hunters.

http://www.wnit.org/outdoorelements/1000/1003/1003.html
Planetarium director Ruth Craft uses a photometer and orrery to simulate the Kepler spacecraft monitoring a star with transiting planets.  In the demonstration, computer software generates a light curve that is projected on the domed ceiling, where visitors can discern the presence and characteristics of companion planets.  See How the Kepler Telescope Works (Segment #3 of Episode #1003); from WNIT Outdoor Elements.

http://smsc.cnes.fr/COROT/
COROT (COnvection, ROtation and planetary Transits) space telescope is international venture launched in December, 2006; it uses stellar seismology to examine the inner structure of stars and a CCD camera to detect the transits of extrasolar planets.  See sidebar in March 2009 Planetarian, page 10.

http://www.mykepler.com/
MyKepler is an educational program with a vision to involve 3,000 schools (1,000 in the USA) in the tracking and exploration of the Kepler telescope data to discover earth-like planets in the close Milky Way proximity.

http://www.planetary.org/explore/topics/extrasolar_planets/extrasolar/transit_photometry.html
Extrasolar Planets: Transit Photometry Method for Finding Earths; from Planetary Society.

http://www.ati.ulg.ac.be/TRAPPIST/Trappist_main/Home.html
TRAPPIST: TRAnsiting Planets and Planetesimals Small Telescope