Proper procedure for updating to mavericks?

OK, so after losing everything the first time I tried to update to Mavericks, I think I have my nerve up to try it again. From what I understand, I should disconnect my external drives this time before upgrading? My Lacie drive had my time machine back ups on it and couldn't be recognized by my mac after the update, even though I don't have any Lacie software on my mac. The install of the update did freeze on me and I had to restart the computer, so don't know if that was more of the issues with data loss. It wouldn't let me migrate my information to Mavericks but treated it like a new instal. I have been reading that some people using external drives are not having any problems with the update??? It is my understanding that I should disconnect all my external drives before attempting it and then restart in safe mode? How does safe mode help? Can someone tell me the steps to properly do this update without hopefully losing my data again. When do I reconnect my external drives...while in safe mode? Do I reboot in normal mode after it works in safe mode? I have a third CCC update that I can use to restore it if all else fails.