Smashing Magazine has an excellent article on ‘the perfect paragraph‘. It’s reminded me of how complacent we’ve become when creating content for websites.
Font sizes of 16 pixels might sounds a bit large, but for me, it represents a challenge to summarise your content using fewer words than you might use with a smaller font. With fewer words, things will be easier to scan and absorb and it will encourage the authors to think more carefully about the message they wish to convey.
I think the 16 pixel recommendation is one of the more useful. Done in conjunction with the other ideas in the article, the key messages will be easily understood, and it will be an subconscious pleasure to read.