Is this the only tax form I have to fill in?
No. You have to fill in a T1, but you also have to fill out Schedule 1 to work out your federal tax and an ON428 form to work out your Ontario tax.

What is this Schedule 1?
When we are talking about income tax, a schedule is just one of a set of special forms. Schedule 1 is where you work out your tax and your federal non-refundable tax credits. If you have investment income - even interest on your savings, you have to fill out Schedule 4. If you want to claim for an eligible dependant, you have to fill out Schedule 5. If you have made donations to charities and you want to claim a credit for these, you have to fill out Schedule 9.

There are a number of other Schedules, but these are the ones most people need to use. They are included with your T1 General package.

What do you mean by taxable income?
Your taxable income is the amount of money that your income tax is calculated on.

What other sorts of income are there?
Good question. First of all, there is your total income.