Not 100% sure what you want for resources under Alt Processes but as far as informational websites...
http://www.alternativephotography.com/ http://www.unblinkingeye.com/http://www.mikeware.co.uk/mikeware/main.html which is good for learning about cyanotype (1 & 2), Argyrotype, Platino-Palladiotype and New Chrysotype (gold salt printing) and has some general instructions for alt process handling and working.
Can't think of anything else right now but those are good to start with.
As far as supplies, for raw chemicals I use Silverprint
http://www.silverprint.co.uk/ Not sure who else supplies "raw chemicals" in the UK to photographers normally.
And I should mention for all those people with hard water that need help clearing cyanotypes and other iron-based processes like Van Dyke Brown, citric acid that is food grade, available at home brew shops or very rarely normal food stores, tends to be cheaper than the photographer stuff and should be fine for just lowering the pH of your wash water.