I'm an organisation development consultant by training (ug) and my preference is to work within democratically structured development organisations. I currently work with the United Nations Association as the London Region Development Officer.
I hope my work style is heavily influenced by many people and disciplines...overall Paulo Friere's student centered democratisation of education (can't find a good link yet!), Carl Rogers' client centered approach in the counselling world (here is some additional material on Rogers) and Edgar Schein's definition of process consultancy - again working from a client centered perspective (not a great link this - I'll find a better one...). Community development as defined by the UN and Association of Metropolitan Authorities is also a focus for me.
The UK's Community Online Forum is worth a look. Sites related to the labour movement in the UK can be found at Poptel. Information for fundraisers is available and the Citizen's Advice Bureau have a searchable site for your queries. Visit John Williamson's listing of youth and community work resources in the UK for a good overview of what's going on. It doesn't cover absolutely everything but is a damn good stab at it.
The Philanthropy Journal may have a foul sounding name (I'm not sold on the patronising nature of concepts like "charity" or "philanthropy"), for not-for-profit resources it's an excellent site. From here take a look at the meta index for not-for-profits, a wealth of information.
The critical management mailing list is hard to beat for quality discussions from a critical theory perspective. The learning organizations mailing list is worth a visit. For hints on strategic planning cycles, this site is interesting. If you have an interest in organisation development linked with a critical theory outlook, do visit the Electronic Journal of Radical Organisation Theory. An excellent site is Sociological Research Online. It "publishes high quality applied sociology, focusing on theoretical, empirical and methodological discussions which engage with current political, cultural and intellectual topics and debates."