Hi Marysia, I will do my best to answer some of your questions as I have just spent a week in HK looking for our accommodation but, I'm new here too.
Firstly, I spent many hours searching this site. It is brilliant and even if some of your questions arn't answered directly you will find answers just by searching. For example, you will find detailed discussions on the cost of living, negotiating rentals, where to get a bargin, restaurants, phone & broadband issues, the list is endless.
I personally like the Kowloon side whereas many expats prefer to live on the island. The MTR & Star Ferry makes life very easy to get around. The Harbour City shopping mall has (apart from 20 million clothes shops) a supermarket, bottle shop, bakery, shoe repairer, book shop....etc., if you're living in TST.
Are you looking for a serviced apartment or non-serviced? Furnished?Budget? Near the Harbour or more suburb style like Jordan, Mongkok? We're in Hung Hom.
For a 2br, furnished, upper quality apt you will not get much change from $45KHKD/month plus (furnished, serviced, views) and that is a smallish space I must add. I didn't see many with a balcony but they do exist. By the way, some one may have a better idea on this than me.
One of the better serviced apartments I saw was in The Gateway.
Another excellent apartment building is The Arch (non-serviced) however, some are unfurnished, leased by the owners or estate agents. It just all depends on what you are looking for and how much you are willing to spend. Both these 2 are very clean with nice views (if you pay more) and they are smack in the middle of the hussle & bussle.
If you post with more details on what you're requiring I will try to help. 