Once you've done some reading about cohousing and decided it may be for you, you're going to want to find like-minded folk to help make it happen. As this site develops, we'll offer more materials here for your use - particularly on the thorny aspects of explaining to officialdom what cohousing is and why they might like it.
Voluntary Action Sheffield has some fantastic and free guides on its website, downloadable in PDF format, that might help get a cohousing group started. We'd especially recommend having a read of the following. None may be exactly what you need, but you'll find something worthwhile: action planning, business planning and constitutions.
We spend a large amount of time and effort trying to improve the way we reach decisions. Here are some extracts of documents on consensus which we have found helpful.