To open your personal account you will need your Hong Kong ID card, passport, some cash and possibly proof of address. Some banks issue the account number and ATM card on the spot depending on the type of account. They will charge you a nominal fee if your balance falls below a specified balance. I would suggest you consider registering for internet banking, the queues can be very long. The biggest is HSBC ( Hong Kong Shanghai Banking Corporation ) and Hang Seng which is part of HSBC; you won't have to go very far to find a branch or ATM. There is one literally on every street corner, also inside MTR stations, so there is no problem on getting your hands on your cash.
Most shops offer EPS, which is essentially a debit payment system instead of paying with cash. Also available in supermarkets and other general outlets is the “Octopus Card”, a travel card that can also store cash. Not all shops and stores take credit cards. Also those that do, like smaller electrical stores will charge you a commission for the privilege, so be prepared. In Hong Kong good old fashion cash has some negotiation power and in some place it is the only form of payment.
The banks are always busy at the counter. You have the option to register for on-line banking, you can also deposit cheques and cash at the machines in the lobby. For cheques you get a scan of the cheque for reference. Intra-bank credits are available to draw on the next day; others go through the clearing bank and can take three to five days to clear. For cheques drawn against a foreign bank and more often than not drawn against a foreign currency, allow three weeks and there will be a nominal charge for the service.
Tax, not much to say about this really other than the rate's are banded between 2%-17% and there are allowances. People are paid gross; it's your responsibility to file your return and pay. The first time you will be assessed for two years, current and projected. The projected year you will get back when you leave or retire. You can pay your tax bill in two instalments and if necessary banks do give loans to pay tax demands. My advice, see an accountant for at least your first Tax Return. If you're taxed globally, there are tax specialists that can help, check the expat press for details. For those who may need some help with their tax bill, the banks do give loans for that purpose.
Hong Kong also has MPF (Mandatory Pension Scheme) that if you don't have an existing pension abroad you will be deducted 5% of salary or a minimum contribution that is matched by your employer. Under the ordinance you are exempt for 13 months but I would recommend you join sooner rather than later. Should you leave HK you can cash it in and take it with you, but you can do this only once. You will receive statements from your provider showing the value of your fund. Change employer and you take the fund with you to your next position.