Invite my parents

I want to invite my parents to visit US.

I'm a H-1B with I-485 pending. Should my parents mention my I-485 pending during the visa appointment?

What kind of material do I need to prepare for my parents applying the B-2 visa?

One friend said that I need to mail my ORIGINAL H-1B approval notice back to my parents, since they need it for their visa appointment. Is it correct?

Thanks.