Although not free like Pixeltalks and Besquare, whose conference video collections ease the agony of not being in countries where these awesome events are held, these Sketchnotes books by Eva-Lotta Lamm are looking really good in my cart right now.
But don’t worry, you can still browse the hundreds of scanned sketches on Flickr, amongst lovely calligraphy to boot. Don’t you just love how the default instinct of the web industry is to share things with the whole world before making a buck?

Kirby Ferguson: Everything is a remix (contd) & Rob Giampetro: Building and Unbuilding & Mandy Brown: The Cut @ Build 2012
Also check out The Sketchnote Handbook from the original sketchnotes guy, Mike Rohde. Free sample chapter can be downloaded here.
Want even more? Visit Sketchnote Army.