Behaviour change for beginners 

Social marketing and behaviour change theories and tools in Plain English

What is social marketing?

First on the list is this website from Centers for Disease Control and Prevention (CDC) has stacks of tools for people interested in health communications and social marketing including a nice introduction to social marketing.

The National Social Marketing Centre case study collection and a set of its own publications that will help you develop your understanding of social marketing. I recommend starting with their Big Pocket Guide (PDF) and then checking out their Starter For 10 teaching resources and Planning Guide and Toolbox. This comprehensive resource splits the social marketing process into six stages, and guides the reader through each one. Every stage, e.g. Getting Started, is accompanied by tools, checklists, self-assessment tools, etc. which can be downloaded and adapted. Requires registration (free). 

Nedra Kline Weinreich has produced a neat introduction to social marketing with a health focus. She also writes a lively blog.

Stages of Change - Prochaska and DiClemente

I'm still looking for the "perfect" plain English descriptions of some of the best-known social marketing theories that communicate effectively without dumbing-down. This explanation of the Stages of Change model is just the ticket for beginners as it is written for a person going through the stages in terms of taking up exercise so has a nice accessible feel to it.