There are a million tutos out there about dual booting, but I just did it today and found it easier than everything I could find and definitely simpler than the last time I had to do it:
* Boot OSX and run the Disk Utility tool. Create a new partition using the free space in your HD. Don't format it, just leave it as free space.
* Download and install
rEFIt. Once you've done that, you can setup Linux as the default OS by editing refit.conf and uncommenting #legacyfirst.
* Insert Ubuntu's CD and restart.
* Hold the ALT key while booting up so you are offered all boot options. Select Ubuntu's CD and install.
* DONE.
No need for Bootcamp or anything, it's as simple as that.
Just a note about how I'm installing Ubuntu these days. Read sometime ago somewhere (sorry, no link) about being able to reinstall Ubuntu without losing your data. It goes like this. When installing Ubuntu, choose manual partitions. You need to create 3 of them, in this order:
* System partition: pick up the space you want, but 15 - 20gb should be enough since it's going to be for the system only. Select "/" as the mounting point.
* SWAP: select it on the combo and pick up at least the size of your RAM.
* Everything else, for the home partition. Select "/home" as the mounting point.
* DONE.
Now, next time you want to reinstall Ubuntu, if you follow the same partition scheme, you will boot up to the new system and all your data will be there. And with "all the data" I mean
all the data: bookmarks, browser history, files, subversion sites and credentials.... Since in the Linux world all user data is (or should be) stored in your home directory, and you don't touch that one when reinstalling, you boot up to a new system with your old data in place. I call that a "dirty" installation as opposed to a "clean" installation when I back up all the files and completely wipe out the hard disk.
As per Ubuntu on the MacBookPro, it's going fairly well. Haven't touched the console for the installation. Just used the proprietary hardware drivers manager (System > Administration > Hardware drivers) for the WiFi and the graphic card. Have to say that after trying the NVIDIA closed drivers I'm sticking with the default ones, seem to do the job for me. Only if you want the F keys to work as normal human beings would expect, you go through
this (using the .conf file method).