instead of relying on websites that want your money (dont even think about starting with it- makes you more dependable as you think) - a google search
http://www.google.com/search?client=...utf-8&oe=utf-8
returns for example the following usefull links:
http://www.friendsofed.com/samples/1590592212.pdf
http://www.smjdesign.com/designwell/...-actionscript/
http://www.netmag.co.uk/zine/flash-1...llax-scrolling
http://webscripts.softpedia.com/scri...ing-21131.html
http://www.actionscript.org/forums/s...ight=parrallax

anything else invovled is general flash Actionscript knowledge