For those that have little/no previous electronics experience, and want to learn, are invited to have a look at a FREE electronic book available online at:
This covers pretty much everything a 'duino user will run into, and includes some handy reference materials and experiments.
Also, folks may want to have a look at some hints and tips on drawing schematic diagrams available at:
http://opencircuitdesign.com/xcircuit/goodschem/goodschem.html
ADMINS: these are some pretty darn good references; it might be worthwhile disseminating them widely 