First, if you're having trouble getting your CD drive open, take your machine to an Apple store and let them look at it, it's the sort of thing that's under warranty.
Is there a small pin hole anywhere on the drive door? If so, stick a paperclip in it and then pull it out with your fingers.
As for starting up into OS X, go to the 'Startup Disk' Control Panel and select the OS X startup folder. Hit the restart button and you should be on your way.
Does this help?