Federation of
Astronomical
Societies

Society for
Popular
Astronomy

British
Astronomical
Association

The British
Astronomical
Association's
Campaign for
Dark Skies

FLD Dark Skies
Cumbria
Campaign

Heavens
Above

Go Stargazing

Universe Today

88 Constellations
and their Brightest Stars
(not an astronomy site
but still interesting)

Backyard Astronomy
Basics
Astronomy for Beginners

AccuWeather
Weather Forecasts

Stellarium
Planetarium Software

Skychart
Draw your own
star-charts for observing sessions

Astroshop
Astronomy
Beginner's Guide

Eddington Astronomical
Society (Kendal)

SharpCap
Astrophotography
Software

NASA Images

PHD²
Telescope Guiding
Software

Siril
Astrophotography
Image Processing
Software

GIMP Image Editor
Open Source Alternative
to Photoshop

ASCOM Mount
and Camera
Controls

Autostakkert
Astrophotography and Video
Stacking Software

FITS Liberator
FITS Standard Image Viewer