Womens weekly also has a couple of books for toddlersI used them for reference when studying childcare and they had some fantastic ideas.
You can also make stamps aout of vegetables esp ones that are getting a bit tatty and you would probably ditch anyway and put paint on them.
Big W has some fantastic books usually the same as the bookstores but half the price.I think the trick is to try and vary so don't put everything out at once maybe stamps one day, pencils the next?
I found this website by Googling activities for toddlers it seemed pretty easy to follow the things and had heaps of ideas along with heaps of other websites
www.preschoolrainbow.org
Good luck I am sure you will have as much fun as he will.
mel