Walk the shop, several times a day. Listen. Watch.
Don't touch anything or pick up anything unless specifically requested to do so.
If it's a union shop, don't even pick up trash; that's someone else's job, and especially if they're not doing it, they'll be first in line to file a grievance against you. There is some incentive for them to entrap you into breaking a rule; they get money, you get yelled at.
Wear your safety glasses, hard hat, boots, whatever is required by the shop rules, whenever you are in the shop. It sets a good example, and also conveys the message that you are not an ivory tower kind of person.
When asked why you're out there, explain that you are trying to understand the real processes as they exist in the shop, which you should be doing anyway, so you have a clear picture of what fairy tales the documented processes actually are.
Most shops have a serious we/they perspective on management, and you have to live in both worlds. You can do that by being honest and polite and respectful toward everyone.
Back in the office, write down what you learned. As the new guy, it will take you a while to associate first names with last names, titles, duties, actual skills, and relationships. A written record speeds up that process. Keep that record for yourself only.
Mike Halloran
Pembroke Pines, FL, USA