Seeds for Change, is a 'non-profit training and support co-op, helping people to organise for action and positive social change'. They run great workshops on effective campaigning, overcoming difficulties, widening support, inclusivity and mutual support, and much more (not to be confused with Seeds of Change, who sell pasta). All organising is based on consensus decision-making principles which saw the harmonious creation of the first Camp for Climate Action and which is such a pleasure to see happening in many grassroots movements across the country today.
Consensus Handbook which brings together many of the guides and shows in a very practical way how we can come to decisions in a way that exclude no-one. There are practical tools on widening participation, helping overcome obstacles, accessibilty, resolving problems etc. You can dowload it for free as a PDF (i think there are about 200 pages) or buy it cheaper from the Seeds website than elsewhere (£4.90 instead of £6).
I'm declaring an interest - I did the illustrations, (but no, I'm not getting royalties!) but my real interest is in helping spread the adoption of consensus decision-making to all organising groups, whether it's a small bunch of people in a city wanting to start a fresh veg co-op or thousands trying to shut down a coal-fired power station.