I am not a HE (hope non-HE aren't banned...), but have plucked many a useful hint off this section, so thought I'd post this in return: I came across this website
www.e-bug.eu/eng_home.aspx?cc=eng&t=Welcome%20to%20e-Bug&ss=1
which offers a fun way in for primary or secondary age pupils to the science of microbes. Enjoy...