There are a lot of sources of tide information on the Web. One of the most popular and useful is the WWW Tide and Current Predictor at http://tbone.biol.sc.edu/tide/ . Like the name says, it has current information, unlike most other sources. However, the location of the sites can be hard to visualize at times. To help with this problem, I have created a little Google Earth mashup. Download either of the files below and open in Google Earth, and you will find placemarks with links to the tbone server to see the predicted current at that site for the next couple of days in the Google Earth browser pane. Presently these are only for the West Coast sites (California and Washington), but it would be easy to do the East and Gulf Coasts.
(Note: Right-click and Save As… Some browsers may try to change the file extensions of .kml and .kmz to .xml and .zip. What a pain.)