Google Maps - Quick and easy to use service with customizable maps, aerial and street views.  Uploads faster than many of the competitors and is always making improvements.  This makes scouting a breeze.  To read more check out this review by BasserDrew.

Maps.live.com – Aside from the traditional aerial and street map views, a special birdseye view makes this site unique for river bassers.  This site may Read the full story

USGS River Data - Provides real time data to a majority or rivers and creeks in your state.

NOAA River Data – Another very reputable weather, water and atmospheric information website that also provides river gauges.

American Whitewater – Data for many rivers in Read the full story