As far as curriculum for toddler/preschoolers I don't have any I'd personally recommend but someone brought up this book on a thread recently.
What has worked for me has been just playing games. It will be too much for a toddler but as your child gets older things like snakes and ladders, uno, mathemagical world, ten frame towers, tangrams, cuisenaire rods might be worth looking at. My four year old loves those.
Depending on how old your toddler is the number blocks TV show is really good.
I say this has worked for me but I have yet to see the final results yet! My oldest (7) was one of two kids out of her class put in the advanced maths class... but she has starting telling me she dislikes maths... hmmm. My youngest is 4 and he loves all things numbers and maths so we'll see.