Another of my all-time favorite illustrators is Quentin Blake (I bet the headline gave the topic away?) I’m providing a link to his website as there is some useful and interesting info there. It’s got a Flash preloader (ugh..) and my first visit there I was kind of confused. As in, ‘I just want to see some of his art!’! But once you kick it around a few times it makes sense and contains a lot of materials.
He has a walk through of how he works on a book and provides his thumbnails and roughs through finished work.
His work is so fresh, lively, active and FUN, it’s hard to imagine someone sweating over it. But as you learn when you draw, making it look easy, simple and FUN is where all the work comes in. Amazing work.