Things I wish people had said at my first job (in light of lots of the people I see starting their first dev gig on here). Please add yours.

Congrats!
Take a breath, you will be fine.
If you get frustrated, take a moment to collect your thoughts.
Don't be afraid to say you don't know, you are not expected to know everything.
Your workday needs to end at a decent time. Don't overdo it or you will be useless for more of your hours.
Always take whatever length of time you think something will take and double it. If you think it will take 15 minutes, it'll probably take your 4 hours.
Concentrate on networking and personal relationships.
Pick the smartest people who have moved the most vertically and pay attention to what they say, they might know a lot.
When management makes an "unwise" or "crazy" decision, ask them why or what the context or motive is that made then arrive at that course of action. Some of them might surprise you in their bigger picture motives or dumbassedness.
Six sigma may be in your future, learn what it is.
Automate as much of your own job as possible.

Um, that's all I've got for now. Hopefully that's helpful to people just starting out. Feel free to add yours.