Ho Chi Minh City Arrivals
Unless you're a citizen of another ASEAN country, you'll probably need to get a visa for Vietnam at your local embassy or consulate.
Passengers on international flights should be given a multi-part immigration / customs form to fill out before arrival. On entering the terminal, follow the signs to immigration. You'll need your passport with the visa along with the customs form for immigration. The queues at immigration can be quite long and move very slowly.
After passing through immigration, you can collect your bags. Once you retrieve your bags, you must stop at the customs counter and submit your passport and immigration form there. They will keep a portion and return your passport along with the departure portion of the form to you. Be sure to keep the immigration card with your passport. You will need to submit it on your departure.