First off, a little bit about building regulations etc:
http://www.fincasdirect.com/en/planning-and-building.html
Permaculture Spain:
http://www.permacultura-es.org/
Projects:
http://www.laciutatverda.org/
http://www.canmasdeu.net/ <- occupied property quite close to Barcelona
http://www.permacultura-montsant.org
http://reddepermaculturaiberica.pbworks.com/w/page/13844757/FrontPage <-- Network of permaculture projects, part of transition network
Nurseries:
http://www.viverosbotanica.com/ <-- Bamboo
http://www.soljardi.com/web_eng/productos.html <-- all kinds of edibles
http://www.viverosalcanar.com/patrones.html <-- citrus
http://www.cultidelta.com/index.asp?i=en
http://www.catalunyaplants.com/
http://www.viverosdecardedeu.com/
Other:
https://guifi.net/ <-- urban internet provider / mesh network that spans big parts of Catalunya (a decentralized peer to peer/node to node network with internet backbone owned by the community with no fees, you just buy the equipment)
http://www20.gencat.cat/portal/site/parcsnaturals/menuitem.1942a21487b35eb0e6789a10b0c0e1a0/?vgnextoid=133ec2acf7a3d310VgnVCM1000008d0c1e0aRCRD&vgnextchannel=133ec2acf7a3d310VgnVCM1000008d0c1e0aRCRD&newLang=en_GB <-- has a list of native fruit species for catalunya (replanting project)
http://www.triodos.com/en/about-triodos-bank/ <-- ethical bank who provides loans for environment and culture businesses or NGOs
http://www.coop57.coop/index.php?lang=ca_es <-- financing co-op that does something similar
http://cooperativa.cat/en/ <- co-op of co-ops in Spain/Catalunya, working to create an alternative to the capitalist market with their own social currency, quite fast growing (documentary:
http://vimeo.com/89454294)
http://calafou.org/ <- connected to cooperative.cat, occupied hacker-space/permaculture/culture center where they work on bitcoin related things, will start working on open source ecology, social currency, etc.
And if anyone is interested in some Spanish modern history, the first thing I would read is George Orwells Homage to Catalunya about his own personal experiences in the Spanish Revolution/Civil War, an absolutely fantastic read. It was these events that inspired him to write Animal Farm and 1984.
If anyone has suggestions I can put them in this list, if not I will update it when I find anything interesting.