How to Select Tools in Photoshop CS6
To select a tool in Photoshop CS6, simply click it in the Tools panel. A small black triangle in the bottom-right corner of a tool slot indicates that more tools are hidden behind that tool on a flyout menu. Click and hold down your desired tool to access the flyout menu. You can also access tools by using keyboard shortcuts.
For the most part, you can access a hidden tool by pressing the Shift key along with the keyboard letter of the visible tool. For example, to select the Pencil tool, which shares the flyout menu with the Brush tool, press Shift+B.
If you don’t like having to press the Shift key to access a hidden tool, choose Edit→Preferences→General (Photoshop→Preferences→General on the Mac) and deselect the Use Shift Key for Tool Switch option. You can then rotate through the tools by pressing the same letter repeatedly.
When you hover your mouse pointer over a tool, color control, or icon, you see a tooltip. The tooltip tells you the name of the tool or icon and its keyboard shortcut, if any. Although helpful at first, it can get annoying after a while. Turn it off by deselecting the Show Tool Tips option in the Interface section of the Preferences dialog box.