You spent weeks sending out cover letters and resumes; you sweated through interview after interview; you waited by the phone for hours with your fingers crossed; finally, you got the job … and then you panicked. Now what?

Dressing for success: It’s not just a cliche “You should never underestimate the importance of dressing professionally in your new job,” say Randall S. Hansen, Ph.D., and Katharine Hansen, authors of Your First Days Working at a New Job: 20 Tips to Help You Make a Great Impression.

When you look like a pro, you’ll feel like one, and your coworkers and your boss will respond to your positive and capable attitude. Don’t be afraid to be creative when dressing conservatively, but keep it tame until you know what’s acceptable and what is just too much. Try to emulate what you saw people wearing when you went in for your interview.

When in doubt, err on the side of caution. “… In the beginning,” say Hansen and Hansen, “even if your department has casual days, you should dress professionally because you never know when you’ll be called out to meet a top manager or key client.”

Make like a Boy Scout There’s nothing like getting to work late on your first day because you didn’t do a dry run ahead of time to find out about traffic and parking problems, pulling out your steno pad to take notes during your orientation session, and realizing you didn’t bring a pen.

As unfair as it seems, first impressions will make a big difference in your career success. Dressing to the nines won’t save you if you’re disorganized and unprepared. Your goal is to come across as confident, capable and reliable, just as you did in the interview you aced to land this killer job.

The key to on-the-job preparedness is to plan ahead. The day or week before your first day at your new job, start making a list of questions you have. If possible, find out ahead of time the name and title of your supervisor and get a copy of your job description. Go to work your first day equipped with well-thought-out questions that will help you learn what you need to do and who can help you do it.

Start taking names During your first days, weeks and months at your new job, you’ll meet dozens of new people. Some of them are people you’ll never see again, but many are folks you’ll deal with every day. “Introduce yourself to everybody,” advises Kate Wendelton, author of The Five O’Clock Club book series. “Be visible – walk around and meet people as soon as possible.”

Carry a small notepad with you everywhere you go in the beginning and write down the names and titles of new people right away. Make a point of knowing receptionists, security guards and custodial staff right away and greet them by name every time you see them. They’re the ones who keep things running smoothly and may be your greatest allies if you run into problems.

No matter what, don’t be afraid to admit when you don’t know someone’s name. You may be embarrassed for a minute, but think how much more embarrassed you’ll be in six months if you still don’t know what to call the person in the cubicle next to you!

Starting a new job can be nerve wracking, but don’t get so wrapped up in the details that you forget how exciting it can be, too. By planning ahead before your first day, you can guarantee a successful, low-stress start.