I cant switch on mac book pro at all, what shall i do?

http://www.apple.com/support/macbookpro

http://www.apple.com/support/macbookair

Mac OS X Forum
https://discussions.apple.com/community/mac_os?view=discussions

http://www.apple.com/support/macbasics/

Isolating Issues in Mac OS

http://support.apple.com/kb/TS1388

https://www.apple.com/support/osx/

https://www.apple.com/support/quickassist/

http://www.apple.com/support/mac101/help/

http://www.apple.com/support/mac101/tour/

Get Help with your Product

http://docs.info.apple.com/article.html?artnum=304725

Apple Mac App Store

https://discussions.apple.com/community/mac_app_store/using_mac_apple_store

How to Buy Mac OS X Mountain Lion/Lion

http://www.apple.com/osx/how-to-upgrade/

TimeMachine 101

https://support.apple.com/kb/HT1427

http://www.apple.com/support/timemachine

Mac OS X Community

https://discussions.apple.com/community/mac_os

Recovery Mode

http://support.apple.com/kb/HT4718

ExpressLane

https://expresslane.apple.com/

Startup Manager: How to select a startup volume

http://support.apple.com/kb/HT131

Startup Key combination: here is the old list:

http://support.apple.com/kb/HT1343

Startup Key combinations new list

Troubleshooting: My computer won't turn on

https://support.apple.com/kb/TS1367

Go step by step.

http://support.apple.com/kb/TS1365

Note: Steps 5 and 6

Step 5

Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

Choose the appropriate method.

Best.