Newbie here

Thats it. Pay at the airport when you arrive.

Thank you so much fir the reply. Relieved

And once you get through immigration and customs you will find yourself outside in the humidity and heat of Saigon (actually it is relatively cool at the moment, surprisingly) and wading through the crowds of milling humanity which throngs the area outside the airport.

If you are going to an hotel or you have an address to go to, make your way through the crowds to your left and get to the taxi rank. Ask one of the attendants there for a VINASUN or a MAILINH taxi (Vinasun are predominantly white cars and Mai Linh are green) because there are one or two rogue taxis operating.

Make a note of the taxi number (not the vehicle registration number) which will be prominently displayed (take a pic with your smart phone), that way if you leave anything in the taxi you have a chance of getting it back.

To make sure that you get to your destination without getting lost (taxi drivers in Vietnam can be hopeless at navigating even with satnav), have the address of your destination written down and, even better, have a Google map showing where you are going in relation to the airport - I show the driver a google map on screen on my phone, whenever i go anywhere by taxi.

Hello RogerDoes,
Welcome to Expat.com.

You already have some good advice. That's it.
Change small amount of USD cash ($300-$400) into VND at the airport.
Later you can change rest of your money (any time) at a better rate from banks and other places in the city.

You've got your Letter of Approval.
Now just stay prepared by filling up the Visa Application form which you'll need to submit along with your letter of approval to get a visa on arrival.

If you are carrying cash and have a plan to open a VN bank acct to deposit it, please declare the cash to the Customs and get a red-stamped document from them. It's hassle-free. No worry.

Welcome to Vietnam!
Cheers

eodmatt wrote:

Make a note of the taxi number (not the vehicle registration number) which will be prominently displayed (take a pic with your smart phone), that way if you leave anything in the taxi you have a chance of getting it back.

Two weeks ago when we took a Mai Linh taxi home from Tan Son Nhat, I left an umbrella behind.  I would've let it go but it was a large windproof umbrella, sturdy from handle to tip, the kind that would safely cover two people through the dirty side of a storm (it did in SIngapore) so I thought I would try to retrieve it. 

I called up Mai Linh, didn't have the taxi number or the driver's name, but knew the route, the fare, and the time of the ride.  The operator was very courteous, helpful, and positive.  She promised to get back to me as soon as she found the driver.  She called back almost immediately, saying the driver was with another ride but he found the umbrella and was keeping it safe.  Since he was in Q7 at that moment (easily 15 km to our place), he didn't show up until 45 minutes later.  I estimated the cost of the ride plus tip for his time and expense.