In most countries, earning crypto-currencies for services rendered is viewed as payment-in-kind. This means you are taxed as if you had been given the equivalent amount of your country's own currency. So, for example, say your salary was paid in part cash and part Bitcoin, and each month you received $1000 worth of Bitcoins, you are taxed like you had just received $1000. If you are paid wholly in Bitcoins, say 5 BTC, then you would use the fair value. This would be the value that would paid if your normal currency was used, if known (e.g. $1000), otherwise you would use the price of Bitcoin at the time to establish your taxable income.
It’s important to keep records of when you received these payments, and the worth of the coins at the time for two tax-related reasons: In terms of an income tax, you’ll need to convert the values to fiat when filing income tax related documents (i.e., the W-2 form in the United States). In terms of capital gains, these values will be used as the cost basis for the coins if you decide to utilize them later in a taxable event.
This data can be added to the Income Tab.