[R-sig-Geo] Very basic figure question

[Rob Forsyth]

A complete geo-tyro demonstrating ignorance here: please be tolerant!

I have a large dataset comprising the results of a questionnaire from  
UK respondents. I am interested in geographic variation in responses  
and have built mixed-effect models incorporating County/Unitary  
Authority/Local Authority (a level of local government in the UK) as a  
factor-level random effect in lme4. Extracting the intercept of the  
random effects I can generate a normalised 0-1 score for each local  
authority. I would like to illustrate the results of this analysis and  
generate a map showing LAs coloured using this normalised score to set  
gray scale.

We have campus access to ArcGIS and related programmes but I have no  
knowledge of these whatsoever and wondered if for this limited task I  
could work within R? Are there any suitable public domain map objects  
and how would I go about this?

Thank you