Themeforest commonly has great lessons. I am unsure if the qualifies for "advanced", but read this series: WordPress for Designers (Days 1-14) by Came Douglass (I possibly could not discover the tutorial pages indexed in the Themeforest site, so I am referencing Simon Baier's compilation):

None which i are conscious of... but you could begin by mentioning towards the WordPress Codex. The details are scattered around a great deal - but that is the way i learnt writing styles and plug ins myself. Top up by staring at the code for existing styles and plug ins and you will be set very quickly.

BTW, are you able to become more specific regarding which facet of Wordpress programming do you enjoy?