Does this help? It appears you can run them on Pages and in Apps, but not on timelines. Also, the rules for businesses are different than for individuals. This article for Search Engine Watch is dated August 29, 2013 and is a good synopsis of the current guidelines. There are also links to some other articles that should help at the bottom of the Search Engine Watch page.
http://searchenginewatch.com/article/2291661/Facebook-Revamps-Contest-Rules-for-Businesses
This is section E: Promotions of the Facebook User Guide
https://www.facebook.com/page_guidelines.php
Promotions
1. If you use Facebook to communicate or administer a promotion (ex: a contest or sweepstakes), you are responsible for the lawful operation of that promotion, including:
a. The official rules;
b. Offer terms and eligibility requirements (ex: age and residency restrictions); and
c. Compliance with applicable rules and regulations governing the promotion and all prizes offered (ex: registration and obtaining necessary regulatory approvals)
2. Promotions on Facebook must include the following:
a. A complete release of Facebook by each entrant or participant.
b. Acknowledgement that the promotion is in no way sponsored, endorsed or administered by, or associated with, Facebook.
3. Promotions may be administered on Pages or within apps on Facebook. Personal Timelines must not be used to administer promotions (ex: “share on your Timeline to enter” or “share on your friend's Timeline to get additional entries” is not permitted).
4. We will not assist you in the administration of your promotion, and you agree that if you use our service to administer your promotion, you do so at your own risk.