Here are some quick tips I give all of my clients prior to their first day on the job:

Prepare

This is a critical task for you and sets up every other thing you do for your first day. You need to get this done 24 hours prior to your first day.

Get all of your paperwork together. Everything that needs to be signed, your license, passport, etc.
Pick your clothes and make sure they look great. You will feel better if they are all laid out and ready to go.
Polish (men) and touch up (ladies) your shoes - they need to look great.
Make your lunch the day before.
Set the timer on your coffeemaker so you wake up to hot coffee.

Meditate

Yes, meditate. When you get up or after your shower, sit on your bed, close your eyes, and relax. Say to yourself:

I will do great. I have years of experience ready to burst out of me.
They love me - they picked me over every other applicant.
I won't screw up - I will ask questions when I am unsure.

Day One is always the hardest day - it is built up with anxiety and fear - meditation will help you get centered. Take 1-2 minutes for yourself.

Leave Early

If your commute is 30 minutes, leave 1 hour early. This is a new route, with new traffic patterns and unknown hazards. Give yourself ample commuting time to get there with enough buffer to ensure you are stress-free and ready to go. If you get there early, that's fine.

Arrive Early/Stay Late

It sends the right message to your superiors, peers and team. It shows you are a 'hard' worker and sets the stage for building your reputation at your organization.

Smile, Smile, Smile

First impressions are made within the first 10 seconds. You are going to meet a lot of people - you don't have to remember their name - but smile and be engaging. It will give them a good sample of who you really are and get you off on the right foot.

Ask Questions

You are not inexperienced, you just need to measure how you will do things, where things are, and what to do with them. If you don't ask questions, you will probably stall and not work as efficiently as you usually would. Get through those obstacles and make things happen!

Try To Eat With Your Boss or Peers

It gives you another chance to quiz them on the more intangible areas of your position/organization. In any event, try to have lunch with all of the people you will touch at your job.

Go Home & Relax

It's been a crazy day. Come home, get into comfy clothes, and lay down on your bed. Embrace the feeling and memories of your new job — review the day with your spouse or partner. This debrief is not only important, it's critical. It allows you to download your thoughts, experiences and emotions.

Go To Bed Early

It's been a tough day — go to bed one hour early to be fresh for the next day!