This is good advice BUT you really need to increase your joint mobility before attempting these lifts.

I would recommend this series of articles to understand the theory behind bad posture and how to fix it.

http://www.t-nation.com/free_online_article/sports_body_trai...

I would spend at least 2 months just improving your joint mobility (especially hip + ankle) before attempting deadlifts. And even then you should really have someone who knows how to do them correctly to coach you.

Else you'll seriously hurt yourself.