That whole thing about having to pay tax twice for the first tax bill...yea thats not accurate.
Er, actually it is accurate. It's called Provisional Tax and is calculated on your expected earnings for the next 12 months. Your first tax bill will include tax on the previous 12 months' earnings plus the Provisional Tax on your expected earnings for the next 12 months.
In subsequent years you will be assessed on the previous 12 months' earnings, and the Provisional Tax you have already paid will be credited against that amount. You will then have to pay the difference plus the Provisional Tax on the expected earnings for the next 12 months, and so on.
Confused??