There are myriad books and magazines that provide information for all levels of photography. Learning techniques from these is easy for some but a nightmare for others. With the advent of YouTube there are now several structured learning programmes, the benefits of which include actually seeing video demonstrations. Just browse YouTube for what you are looking for, but to start you off here are some particularly good sites.
Waylandscape is a site run by and dedicated to the landscape photography of Gary Waidson, a regular speaker on the L&CPU circuit and beyond. Gary features prominently in the Take a View Landscape Photographer of the Year competitions and his site has tips on how to get the best out of your camera.
The web's most comprehensive site devoted to the art of landscape, nature and documentary photography using digital as well as traditional image processing techniques. You will find on these pages instructive feature articles, product reviews, travel and technical discussions, inspiring portfolios, and a Discussion Forum.
Fotospeed is principally a supplier of high quality papers and inks. They produce continuous ink flow systems for Epson and Canon printers and will provide free of charge printer profiles for users of their own brand papers and inks. Additionally, they publish a blog with comprehensive advice on photo techniques and ideas for subjects for every month of the year.
ASTRONOMY AND TIME LAPSE
Pixel-Peeper is a lens and camera comparison site. You can examine full size pictures from a specific lens or camera, (more than 1,000,000 photos are available), also based on a specific setting (e.g. aperture, focal length or ISO). If you'd like to find out more about how to interpret sample images, check out the tutorial. Each lens/camera page also lists a number of online stores and eBay auctions along with availability that you can use to purchase equipment, or simply to check prices.
For detailed camera reviews the following are useful sites.