Color Selection tool for maps. Use this tool to see what colors work in color ramps, etc. ColorBrewer.
Some general sites of interest; not meant to be a complete list of GIS resources:
Data Catalog-MEGIS Data Catalog and more
ME Aerial Photo viewer-Online mapper from MEGIS
Satellite Oceanography Lab at University of Maine; includes sea surface temperature, true color, chlorophyll, etc.
GRANIT-NH GIS - New Hampshire GIS home page
Historic USGS Maps of New England and NY
Census of Marine Life - Gulf of Maine - Consortium of data on the marine environment.
Northeast Ocean Data Portal - Data, tools, and information for Coastal and Marine Spatial Planning (CMSP) decision support in the northeastern United States; from NERACOOS.
U.S. Fish and Wildlife Service:
Region 5 Cartography and Spatial Data Services
USFWS National GIS Site-also contains good links to data and tools
Fish Passage Decision Support System
National Wetlands Mapper
Add NWI data to ArcMap via a GIS/Web Server
State and county demographic profiles-quick and easy access to facts about people, business and geography; US Census Bureau
Data.gov - U.S. Maps and Data. Formerly Geodata.gov
EPA BASINS - watershed assessment and modeling tool
EPA GeoData Gateway
The National Map - USGS collaborative to deliver maps to the nation.
NILS-National Integrated Land System; cadastral records management partnership
National Inventory of Dams-Army Corps of Engineers
USDA Geospatial Data Gateway -Natural resources/environmental data
Earth Explorer - Satellite images, aerial photographs and carto products from USGS
Glovis - Global Visualization Viewer from USGS/EROS
CLICK - Center for LIDAR information coordination and knowledge; USGS
NDEP - National Digital Elevation Program
Landsat - NASA/USGS imagery program starting in the 1970's.
NOAA Digital Coast - tools, training, data for coastal resource management.
MRLC-Multi-Resolution Land Characteristics; National Land Cover Database (NLCD)
NAIP-National Agriculture Imagery Program; focus on aerial imagery during growing seasons.
Digital Globe - high resolution commercial imagery
GeoEye - high resolution commercial imagery