Unfortunately, the Nimitz class carriers are unable to fit through the Panama Canal. They are just too big.
As for Wikipedia, don't believe everything that is on there, because anyone can edit the entry at any time. It is a good start, but verify the info if you want to quote it. For instance, if it says the USS NIMITZ itself is in San Diego and does Med Cruises, well thats obviously in error.
Each carrier has a homeport, and it could change (almost all have I think). The East coast ships generally go on Mediterainian cruises, where they will normally patrol the Med and the Atlantic Ocean. West coast carriers usually do Pacific cruises that patrol the Pacific and Indian Ocean Area of Responsibility (AOR). If required, the Navy can deploy the carriers to either coast fairly quickly, but in recent times this entails the east coast ships transiting the Suez Canal to get to the Indian Ocean (and Persian Gulf region). Smaller Naval vessels will go through the Panama Canal to get to 'other' coast, but if a carrier needs to change homeports, a lot of times they will do so at the end of a 6-month deployment and just go around the world.