I have been teaching English in Hanoi for about a year and a half. My background is in finance. I came to Hanoi with no teaching experience. I took a TEFL (teaching English as a foreign language) course in Sydney before coming to Hanoi. There are many options for teaching English here, such as language schools, universities, public schools and kindergartens as well as tutoring.
Most people I know work in language schools which are popping up everywhere around town. They usually have some tutoring on the side. Learning English is very popular here and with money continuing to flow into the country and the population having more disposable income; parents are opting to send their kids to English lessons. With higher incomes and a high young population (I heard somewhere that 65% of the population are under 30) it makes for an attractive teaching environment.
The majority of classes are with kids or teenagers however there are adult classes as well. The levels range from beginners to advanced students planning to study abroad.
I have worked for a number of language schools in Hanoi. The choice you need to make is whether to go with a bigger, more reputable school or a smaller Mum and Dad type of set up. The bigger schools such as Language Link and Apollo will give you a contract, paying for things like insurance and holidays. They have a good selection of resources and are much better for social interactions. At Language Link there is a teachers room where teachers can prepare their lessons and chat with each other. They will pay you around the $18 per hour mark. They are generally the lower end of the pay scale in Hanoi. You have the option of a full time or part time contract. A full time contract is a minimum of 70 hours per week.
The Mum and Dad type schools, which usually operate out of a big house, are generally more relaxed and flexible. They also, generally, don't have contracts. The first school I worked for didn't have a contract and in the end I got screwed some of my wages. They were a small company; terribly run with little to no organisation, inefficient and of poor quality. I knew from the outset they were a rubbish company so I take the blame for sticking with them and not getting some of my money. The company was called Ninemoon English centre. They paid $20 per hour but I would avoid at all costs. The majority of the work I have done in Hanoi has been without a contract. This comes with added risk but I have had no other issues with employers and commonsense, along with a little word-of-mouth, usually prevails. I have earned between $24-33 per hour - cash in hand. They don't have the benefits of the bigger schools but in my experience the extra money they offer makes up the difference and more.
Once working for a school you will generally get offers for tutoring. I have done this throughout the whole time I have been here. You can ask from around the $25 per hour mark.
Hanoi is a great city to find work. There are many jobs and if you are a good teacher you will find work easily; regardless of experience. The Vietnamese students are generally great and look for a fun, interactive teacher. Creating a happy, enjoyable learning environment, for both kids and adults, will give you many teaching opportunities in Hanoi.