Hi as a new beginner of bitcoins. I need some professional help and guidance. I have several questions and I hope that by starting this topic other newbies like me can also receive help.

The questions are as below:
1. What do I need to start mining bitcoin?
2. Where do I mine bitcoin from?
3. Is it really efficient if your electrical bills are really expensive?
4. What is the most efficient way to mine for bitcoin?

I really hope that you guys can help me answer these questions.
I thank you all in advance.