Here's the link on the AA site:
http://www.aa.com/i18n/AAdvantage/ea.../e-Rewards.jsp
Once you click through there to the e-rewards site, you'll select your country ("US and CA only at this time") and language. The next page will ask for your AA account number and other info. Once you confirm your account (via email to you) it lets you take a survey about flying.
For good measure I took a couple surveys that took a minute and then switched my email address to a
10minutemail address to avoid spam in the future (you should probably do this from the beginning and write down the email address to avoid spam. That way you can avoid spam, but still log into the e-rewards account if you want to do so).
We'll see if I get credited my 250 miles ever!