The blinking question mark is a sign that your machine cannot access the boot/startup drive. Not sure what to make of the blank grey screen.
What instructions are you referring too?
How old is your machine? What type of drive do you have?
Give it a virtual kick.
Resetting your Mac's PRAM and NVRAM
http://docs.info.apple.com/article.html?artnum=2238
http://discussions.apple.com/thread.jspa?messageID=3497603�
power down machine.
hold down the option/alt key
continue holding
you should get a list if startup drives. less ten 10 seconds
You should boot up in recovery mode. command + r
see if you can run disk repair
Report back.
R