Here are some last minute tidbits for circuits that I thought students with enjoy.
http://www.andythelwell.com/blobz/
http://www.ndt-ed.org/EducationResources/HighSchool/Electricity/seriescircuit.htm
http://www.ndt-ed.org/EducationResources/HighSchool/Electricity/parallelcircuit.htm