Are the rules for 7 Wonders and the expansions available online?
Yes, you can find them on the offical website of Repos Production (rprod.com):
7 Wonders base game
http://rprod.com/index.php?page=download-2 (there you can find the Quick Rules, too)
Wonder Pack extension
http://rprod.com/index.php?page=download-18 (there you can find the Quick Rules, too)