The Spirit of Gardening http://www.gardendigest.com/ If it too wet, miserable or otherwise to be out, this is a delighful and deep resource that will cheer you up and may even inspire you to greater levels.
The Postcode Plants Database http://www.nhm.ac.uk/science/projects/fff/Intro.htm If you are committed to natural gardens and native species this is a fantastic resource run by the Natural History Museum and worth adding to your favourite sites for regular visits.