DEferred Tax Confusion

hi mIke,
due to some probs i got late n hav startd preparing nw…. em very very much confused with Deferred tax….even i passed f7 without any knowledge of derred tax…
my questions are:
1.What is xactly current tax?
2. Which amount do we pay to tax authorities? Currents tax or Income tax expense in profit or loss?
3. If we hav carrying value of $40k and tax base of $36k…the income tax would obviously b greater as less dep is charged resulting in high profit then how does it beomes a deferred tax liabilty where as we hav charged a higher amunt of tax than tax base..??shudnt it b an asset for us? this confusion is killing me
4.Why do we use a single a tax rate e.g 30% when diffrent tax reates are used in tax base? what is the difference between corporate tax rate and the tax rates of tax authorities?
5. Is the tax rate and income tax expense in incom statement an estimate to detremine the value ox tax liabilty at the end of tax year and then they are compared ?

please please help me with it…..i will b grateful to u…..