You may also find an icon that allows you to have a window that is neither minimized or maximized. You can make this window just about any size you want by dragging the sides or corners. Play around with this feature in your paint program until you are confident you can make it any size you want.
You can also move a resizable window. Usually this is done by dragging the TITLE BAR (often it is a dark color, and it usually has the name of the program or the file). Try moving your paintbrush picture around as well.
The resizing and moving options are useful when you have more than one program running at a time.
Many operating systems also have a tile command available on the menus that automatically give each program you have open the same amount of space on the screen. This can be a very handy feature.