I recommend the following websites and literature:

http://www.shamanism.dk Jonathan Horwitz and Annette Høst run excellent shamanic workshops in Britain and Europe.  They run 'Basic Workshops' to introduce 'core' (accessible to all, non-denominational) shamanism regularly in London, and are not too expensive.  I have attended workshops run by others, but have found these to really open the space for spiritual magic to be held.  They also run an extensive programme of 'Advanced' workshops on many, varied topics.

http://ancienthealingways.co.uk In the timeless open space of Snowdonia's mystical mountains, Ancient Healing Ways invites you to explore, experience and 'just be' deeper inside yourself and the magic of the natural world.  The courses are nature-based spiritual practices rooted in indigenous and shamanic traditions. If you are one who dares to look inside your being; one who wishes to cross the shore to arrive more fully into the 'present' and come closer to your true nature, they offer you initiatory courses including Vision Quest and Ancient Council. They promise to touch your primal essence from the wild and edge-y to the eternal nature of a flower or a mountain. Supported with safety and kindness, they carry these old ways to open hearts and honour our beloved earth. Pippa Bondy has been working shamanically for many years, and works deeply and extensively with the Directions, Nature, Council and the Vision Quest, amongst many other important things.

http://www.sacredhoop.org  Sacred Hoop Magazine, for Shamanism, Animism and Sacred Earth wisdom.  Bringing the ancient traditions of the world to people here an now, in ways that are relevant and practical.  This is the website of the main shamanic magazine in Britain.  Many articles, contacts and advertisements can be found in these pages if you're looking for more work.  Subscription is quarterly and very reasonable.

I also recommend the following reading (all available at http://www.amazon.co.uk):

On shamanism in general:

Your Shamanic Path, Leo Rutherford

The Way of the Shaman, Michael Harner

The Spirits are Always with Me, J. Shutt

On soul retrieval:

Soul Retrieval, S. Ingerman.

On deepening our connection to spirit:

A Path with Heart, J. Kornfield.

Stillness Speaks, E. Tolle.

For fun:

His Dark Materials trilogy, P. Pullman

On homoeopathy:

As my journey into homoeopathy came at the suggestion of spirits, I am very happy to offer a homoeopathic practice as a fully trained and registered homeopath.  Please see www.joannashipley.co.uk for more information.

And there are many, many more!