Even if you're looking forward to the new start, your first few days at a new job can be rough. Rather than stew in your gawkiness or wait to be engaged, take the initiative.
Richard Moy over at The Muse provides a number of suggestions, such as striking up conversations in communal areas and trying new things with co-workers, but from personal experience, the best idea of the bunch is to take colleagues to lunch.
It's a combination of Moy's first and second suggestions and while not applicable to all jobs, it's better to get to know people in a less formal setting, rather than a boardroom or office.
You'll quickly get an idea of the relationship dynamic you'll have — heck, you might even make a new friend or two. There are some indirect benefits as well: learning the lay of the land, finding good places to eat and the potential to learn enlightening facts about your workplace you wouldn't otherwise hear by being inside it.