Really like Ed Emberlely's books. Great for all ages - makes drawing accessible to those who don't think they can draw.
Step by step instructions.
I've been getting my books at BookDepository. It's based in Guernsey, United Kingdom. You can shop in NZ dollars,
shipping is free and everything I've looked for so far is cheaper than
buying from here in NZ. It takes a couple of weeks to arrive, but well
worth the wait.