The RHS site has a lot of good information, including what to do in the garden month by month. I am an occasional gardener but am taking to heart the advice to sow hardy annuals, herbs and wild flower seed outdoors, in April.
I love this little Saxon poem that summarises the seasons:
Spring: Slippy, drippy, nippy;
Summer: Showery, flowery, bowery;
Autumn: Hoppy, croppy, poppy;
Winter: Wheezy, sneezy, breezy.
Picture: Spring by Pieter Brueghel the Younger