where to start to remember the Flash?

Colin Mook and again Colin MUK! he has some good books and articles on the subject, on his site there's a lot of interesting, including and presentations. I advise you to watch his video: "Lost Actionscript Weekend" (link not give intended), where he raskladyvaem on the shelves starting with the basics, what you should be. and read flasher.ru — good for your health!

With the transition to AS3 of course. Essentials Cookbook.