If you wanna try Ubuntu and prefer a Mac like experience then 11.04, 11.10 or the forthcoming 12.04 distros are for you Pro.
If you prefer an interface more "Windozelike" then I'd install 11.04 as this is the last distro allowing the Gnome desktop option (unless 12.04 again allows that option).
After installation of 11.04 in the start-up process after you input your username, when the screen comes up to input your password you'll see some options at the bottom edge of the screen. I "think" if you click on "interface" you'll have the option of using "Ubuntu Classic Desktop", which is the Gnome GUI/interface.
If however in the installation process you opted for the automatic login then when you fire up it will take you directly to the standard 11.04 (and newer distros) Unity interface, which I despise with a passion, but that's just my preference, so YMMV.
If you have enabled automatic login and wanna have the option of the Gnome desktop you'll have to go to System->Administration->Login Screen->Unlock, then enter your password and change the settings to allow logging in manually to then give you the option to switch to the Gnome desktop in the start up process.
If you prefer the Ubuntu Classic Desktop(Gnome) then once you have selected it during the start up process it will become the default desktop without any further action, same thing if you prefer the Unity desktop.
Though I've been onboard with Ubuntu since 6.06, unless they again offer the Gnome desktop option in the future, I'll problee just stick with 11.04
BTW, the best tech support is havin a 2nd mosheen to search for forum/troubleshooting help. It's saved my bacon on more than one occasion