The Toolbar is the area in your FCKeditor where all of the functions are hidden. Every button on the toolbar access a different function of the editor. There are simple fucntions like copying or pasting and more advanded ones like inserting links or tables.
To use the buttons on the toolbar you have to point your mouse coursor on the button. The button will highlight with a blue square around it and a message with the information about the button's function will appear. If you want to use this function just press the button by clicking it. In time you will learn abou all the functions od the FCKeditor and you won't have to read the discription of the button, you will just press it intuitively.
Besides the toolbars buttons there are also toolbars context menus. The toolbars context menus are the white areas with a litlle arrow on its right side and a text regarding to its function on the left. It can be easily accessed by clicking on the white area or the litlle arow. After clicking the menu will expand and you will see the functions. To access one of them simply click it.