Below is the process to use BitMinter for mining −
Step 1 − First, we signup with BitMinter site using our google or yahoo mail accounts and then confirm our mail id by clicking on the link in our mail received from BitMinter.
Step 2 − We set up a Worker account with a worker name and worker password besides the username created when creating BitMinter account. We link the Bitminter Client to the worker account.
Step 3 − Then we log in by filling up account details as shown below.

Step 4 − After this by opening the BitMinter Client application, we get following console as shown below −

Step 5 − We press the Engine Start button to start mining. We have to ensure that our machine clocks a hashrate speed of atleast 25 million hashes/second or 25 M H/s.
Step 6 − We will also need to change a few settings regarding automation. We can leave our machine on all day and all night.
Step 7 − We can go to Settings > Options to change these settings. Automated devices are a list of devices that you set so that they start automatically when the software starts.
Step 8 − We will let our machine run at night increasing the prospect of making more number of bitcoins.
Mining secures the transactions by finding random strings that make the block to hash to a value with lot of leading zeros. The more the zeros, the more difficult it is to decrypt. Mining bitcoins does not mean finding new bitcoins; these are awarded by the network for completing validation of all outstanding transactions of a block and solving some complex math puzzle.