For some reason not clear to most Linux users, Gnome Desktop 3.x series was shipped out without maximize and minimize buttons by default. It also does not allow Desktop icons by default.
Good news is, Gnome tweak tool solves all of the mess. Yes! it is a mess from an end users point of view.
It isn’t clear of Gnome-tweak-tool is owned by the Gnome Project but it works perfectly.
For Ubuntu 11.04:
$ sudo add-apt-repository ppa:gnome3-team/gnome3
$ sudo apt-get update
$ sudo apt-get install gnome-tweak-tool
For Fedora 15:
$ sudo yum install gnome-tweak-tool
Additional features can be done with this great tool.
When done with the installation run the application and go to click on Shell. In the drop down menu for Arrangement of buttons in the title bar, pick All.
Just press ALT+F2, enter “r” (without the quotes) and hit Enter. Your windows should have the minimize and maximize buttons now.
Finally, Tweak Advanced Settings tool can also be used to do a lot of other stuffs such as changing the font, changing the theme etc.