The Guardian has been running a series of features on modern paganism. They are written by Liz Williams and are very informative, although obviously aimed at non-pagans who want to learn what it's all about.
I linked to parts 1 and 2 earlier:
1: What is Modern Paganism
2: How Does One Become a Druid?
Here are links to parts 3 and 4:
3: The Wheel of the Year
4: The Literary and Artistic Underpinnings
If you want to find out more about paganism, here is a link to a feature I wrote some time ago on finding out the basics about Wicca and witchcraft