As a new hire, the process of proving your worth is just beginning. The most successful new hires are the ones who exhibit certain traits and behaviors in their first three months on the job.
Listen, Learn and Observe
Understanding the culture of the organization should be your top priority. That means more listening and a lot less talking.
Pay attention to the social patterns and daily rhythms. What are the norms? Do people use IM? Do they schedule calls on weekends, or only during the typical work hours (I'm not exactly sure what that means anymore, but you get the idea)?
What is "normal" for your company when it comes to communication?
As a former English major and litigator, I've always written long memos on important topics. But recently, I've started writing more and more single-page memos with the classic memo headings (FROM, TO, CC, RE and DATE) rather than long e-mails. In fact, we have a college English professor available to our executives for editing and writing support.
Stay on the periphery. Observe how the leaders lead and the managers manage. How are decisions made, and who makes them? What are the patterns of communication, the non-verbal Morse code, the subtle tone and style of emails -- including who is included (or not) on the CC line? Is using BCC acceptable, or viewed as sneaky?
It takes time to understand the ebbs, flows and cycles of business communication. Often the cycle will shift near the end of the month or quarter.
Watch and learn before you open your mouth.
Be Deliberate About First Impressions
Perceptions, especially first impressions, are quick, complex and often inaccurate, despite many people's professed confidence that they make good judgments instantaneously. Remember, if you are new to a job, you are working with a reservoir of goodwill filled by the expectations of those who advocated for you, and your promise to meet and exceed those expectations.
You can either impress, or fail to impress against those expectations. Don't jump at a chance just because you are eager to impress. Be patient and wait for the right opportunity to deliver spectacularly.
Complete assignments that exceed the scope of what was originally asked of you.
Be gracious with support staff like IT and HR when they need your attention.
Ask questions -- especially when you don't understand a process or assignment -- rather than working around it or insisting on your own approach.
Leverage Your Perspective
I've talked before about the "smart stranger" concept -- the idea that an outsider's perspective can be a driver of innovation.
As a new employee, you have a built-in (but fleeting) advantage: fresh eyes. Look for opportunities to try new things or improve upon the status quo.
Avoid at all times starting a statement with "At [where you used to work], we did it this way."
News flash: You don't work there anymore. If you have a better idea for how to do something, use your observations and knowledge of the company to introduce it in such a way that your colleagues will be receptive.
Take ownership of your ideas and improve upon what you've seen.
And above all else, pour yourself into over-delivering against expectations.
You will only have one chance to make that first impression.