in employment negotations, the only time you should start signing anything is when you have a job offer letter in hand with the salary you want, and the name of your manager, both in writing on that letter.

(rare exception: sometimes you might get asked to sign an NDA prior to being brought in for an onsite interview. even then, I would think very very carefully about signing it.)

My two cents: don't put companies on a pedestal -- we are certainly nothing special to them, after all. don't do anything you're not 100% comfortable about.