There is a need for specialised equipment for mining the Bitcoins. You have to have a very fast machine with a calculation power of 50 to 50 Mhash/sec per CPU. Each complex calculation solved will earn your group 25 Bitcoins(earlier it was 50 Bitcoins per solution). If you have the necessary equipment, you have to download the GUIMiner program and sign in with your user name, worker id and password. Your Bitcoins are saved into a online wallet and they are tradeable on MtGox and other sites.
Right now the Bitcoin is going at about $ 119.30 (Rs.6483.00) whereas in the morning it was trading at around $225.00. If you are into computers and are interested please visit this tutorial. You can also check whether your equipment will give you any returns by visiting this page which is called the Bitcoin Mining Profitability Calculator
You can get the realtime Bitcoin rate without logging in at Preev.com.
Further information can also be had a Google search or visiting this site, where Alex Wawro has given a nice article regarding Bitcoin alongwith this drawing.
Hope you got the general idea of how this regulation free money works. Please post in your comments regarding this article or any help that you may need.