Excerpted from “Adobe Acrobat 7 for Windows and Macintosh: Visual QuickStart Guide” by Jennifer Alspach
When you want to make your opinion heard, use the Note tool in Adobe® Acrobat® 7.0. Notes are the most basic and common form of comments in Acrobat. Think of them as notes that you can stick onto your documents. You can use notes to keep track of changes or to indicate changes you'd like to see in the text without actually making them. Because you can choose (in the Print dialog box) to have notes hidden in the printed document, you can also use them to add information that's hidden from the public.
To create a note:
With a document open, choose the Note tool (Figure 1) from the Commenting toolbar.

Figure 1: Choose the Note tool from the Commenting toolbar.
Place the note by clicking the document page where you want the note icon to be shown. A note appears in the default size, with the name of the note's author and the date and time at the top (Figure 2). If you'd like to change the size of the note box, click the lower-right corner with the Hand tool and drag to the desired size.

Figure 2: A note of the default size is created when you just click.
Type your note in the box.
Click the close box in the top-right corner of the note to close the note when you've finished entering text (Figure 3). A note icon remains in the document at the spot you clicked to create the note.

Figure 3: Close the note by clicking in the box in the note’s upper-right corner.
To edit an existing note:
Double-click the note icon to expand the note.
Click in the existing text to place the insertion point at the desired location.
Edit the text as desired, including cutting or copying text or pasting it from another location.
Tip: You can edit or delete notes while the Hand tool is selected.
Choose Edit > Preferences > General (Ctrl-K/Command-K) to open the Preferences dialog box.
Select Commenting in the list of categories on the left side of the dialog box (Figure 4).

Figure 4: Select Commenting in the list on the left to change the preference for comments.
Choose the font size from the pop-up menus, and set the opacity of the note boxes and the behavior of various types of comments.
Right-click/Control-click the note icon and then choose Properties from the contextual menu (Figure 5). You can also choose Properties from the Options arrow in the note. The Note Properties dialog box opens.

Figure 5: Right-click/Control-click to access the contextual menu for Properties.
Click the Appearance tab.
Click the Color button to select a standard color. Or, choose Other Color at the bottom. This brings up your system's color picker dialog box (Figure 6).

Figure 6: If you use a Mac, the dialog box for your color picker might look like this.
Choose a different color, and click OK to close the Color Picker.
Click Close in the Properties dialog box to change the note's color.
Tip: To move a note, choose a different tool (such as the Hand tool), click on the note, and drag it to a new location.
Right-click/Control-click the note icon and then choose Properties from the contextu¬al menu. You can also choose Properties from the Options arrow in the note. The Note Properties dialog box opens.
Click the Appearance tab.
Under the Icon list, choose a different icon for your note. Choose from a variety of icons. To see your new icon, click on it and look at the document (Figure 7).

Figure 7: Select the note icon you want in the Note Properties dialog box. You can see the new note icon when you click on the document.