Whether it's day one, or day 101, always show initiative at work.
Allow me to relate a personal story: While in college, I worked as a desk associate for one of the major TV/radio networks in New York City. I assisted the producers with phone calls to reporters and possible interview leads, gathered facts for news stories and uploaded the week's podcasts to the network's website.
One night, while working the graveyard shift, I hung my coat over my chair and sat down as usual. Then I noticed two huge cardboard boxes on the floor behind me. Inside the boxes were office supplies-paper towels, printer cartridges, pens and so forth. I had never been told that it was my job to put away these supplies, but things were quiet in the newsroom and I knew where they all belonged, so I put everything away as efficiently as I could and sat back down in my chair.
Not more than a minute later, the assignment editor (my boss) popped his head up from behind his computer screen and said, "Do you know that four desk associates have come in before you, saw those supplies sitting there and not one of them even offered to put them away, let alone took the initiative to do so? Thank you!"
Whether it's going above and beyond your role or helping out with a task that just has to get done (like putting office supplies away), take the initiative. It conveys a dedicated work ethic, a "team player" attitude and a personal ideology that menial office tasks are not "beneath you."