Pen Tool - used to create shapes with fills, or paths that can later be saved to be used as selections repeatedly. There are various pen tools. these follow below.

Your basic pen tool will allow you to create anchor points by clicking to cover a specific area or to create a shape of your choice, which can serve to create a selection or a fill. To do this select the pen tool from the tool palette menu and begin to create points to get a sense of how it works. The best way to understand this tool is to use it. Evaluate how once you create points after your first you can adjust the shape of the line according to where you drag your mouse. (Try moving left or right to get a sense of this.)

The Free transform Pen Tool is similar to the pen tool, only you can drag this one, much in the same way as your basic lasso tool.

Add Anchor Point Tool - used to add points to an already created Path. You can also access this tool when using your basic pen tool by holding down the apple key. A plus sign will appear right next to the pen cursor.

Delete Anchor Point Tool - use this tool to delete points. To use it select it, then go up to the point you want to delete. a minus sign will appear, then press.

Convert Point Tool - used to adjust points. To use this tool, select it, then go up to the point you want to adjust, then press and adjust as desired. Controls handles will appear as you adjust your anchor point.

Create a path with no color (with option to fill): choose the pen tool then at the top, choose the option "paths" then begin to create a work path. When you are done with the work path, you can save it by double clicking it in the path palette, then choose a name. You can then load the path as a selection, or choose to fill it, by clicking on the corresponding buttons at the bottom of the palettte.

Rectangle and other tools - are preset paths that can be filled or laid out empty depending on the options you choose at the top of the menu.

Bucket Tool - used to fill areas witth desired color. To select a color, double click on the color palette at the bottom of the tool palette menu, or select a color directly on the color menu control window (if not visible then select it from the top menu: Window > Color)