Friut and Vegie Info
the above has good information on fruit seasons and how to select good fruit - you can down load the original report from there as well. It also has a link to farmers markets near you - always a good way to ensure fresh produce.
Nutritional values is harder to find - there are plenty of sites out there but it's hard to know whether the source is trustworthy.
re: purple goddess
PG as much as I love ya, there's little to find on solemama that fulfils the OP's requirements.
I'd suggest checking out some of the market authorities.
Sydney - seasonal produce guide http://www.sydneymarkets.com.au/produce/seasonal_produce.html
Melbourne - http://www.marketfresh.com.au/main_me...
also for australia check out cuisine.com.au which has an archive of Steve Manfredi's seasonal produce
And Gourmet traveller online (gourmettraveller.com.au) also does a seasonal thing usuall written by hunky Hugh Wennerbom (not my words)