Is there any web sites where I can get information about working priciples of Drill Rigs & Drill bits?

Answer 1

Sure, just search on it. The thing about searching, tho, is that you need to know how to input keywords for an advanced search so that you don't turn up a lot of irrelevant garbage.
Here, search on drill rig bit "working principles". Put the words in the order of importance in the seach, and put "working principles" in quotes. that way you'll get the number of hits down to a managable number and more relevant hits.
http://en.wikipedia.org/wiki/Drill_bits
http://www.answers.com/topic/drill-bit-1
http://http://www.answers.com/topic/drill-bit-1
http://experts.about.com/e/d/dr/drill_bit.htm
http://www.well-drillers.com/2003_Workshop_Details.pdf

Answer 2

A drilling rig is a structure housing equipment used to drill into underground reservoirs for water, oil, or natural gas, or into sub-surface mineral deposits. The term can refer to a land-based structure, or a marine-based structure (oil platform) commonly called an 'offshore oil rig'. While marine-based rigs can drill through the ocean bottom for minerals, the technology and economics of under-sea mines is not yet commercially viable. The term "rig" therefore generally refers to the complex of equipment that is used to drill the surface of the the earth's crust for samples of oil, water, or minerals.
See...
http://en.wikipedia.org/wiki/Drilling_rig
http://www.well-drillers.com/2003_Workshop_Details.pdf
for more details.