I recently gave a course at the University of Potsdam about scripting in uDig. Since I didn't want me to take again more than a year to get this to you all (see here), I posted them already to slideshare.
This will soon be converted to a tutorial for the uDig community and available from its documentation section.
It will also be the big version of what I am going to present as a workshop to this years FOSS4G. Lets see if it gets picked.