Prefecture and Municipal Tax

I've worked in Tokyo since Feb this year. Currently, I am deciding my return date/end date at work and one of the consideration is the prefecture and municipal tax which seems to be levied if I stay in Tokyo pass 31 December. Does anyone have any solid information as to whether it is true that I will be charged almost a monthly salary for Prefectural and Municipal tax if I stay here pass 31 December, even though I have not been in Tokyo for 1year or more?

If I want to avoid been charged the P&M tax, and decided to leave Japan prior to 31 December, but I will return after the new year 2009 on a different visa (non-working, holiday visa), but still stay at the same place as I am currently residing, would I be charged the P&M tax?
Does anyone know any good government authority to whom I can seek these tax advices?

Thanks many ahead!

I don't think you will be taxed any amount until from about April or so 2009. The amount you are taxed is based on your previous year's salary. I usually get my tax bill in April or May. So as far as I know you won't get taxed until April or so 2009.
I am not too familiar with the laws, but if you went to your local ward or city office, I am sure they will have the information in English if needed. Also, there should be someone else here that can give you more information than I can.