How much do I earn?
There is no good way to calculate what you are going to earn today or tomorrow. Most of it is luck. You can go months without finding any blocks and suddenly you find 10 blocks in a single week. Everybody has good and bad days and there is no way to predict them.
To get an estimate of how much you earn you can go to: http://burstcoin.biz/calculator. To use it you simply input your mining capacity. You don't need to change any of the other numbers. They are calculated from the last block. You are able to change them to see how you are going to perform in the future.
Coins Per Block: The currently reward for winning a block. It will never go up, but only go down with a rate of 5% each month.
Base Target: How hard it is to mine. It will change to according to the current network capacity, keeping the average block time to 4 minutes.