Open your Internet browser and research different websites that allow you to create comic strips and books for free. Examples of such sites include http://www.makebeliefscomix.com/Comix/ and http://www.readwritethink.org/files/resources/interactives/comic/.
Enter the name of your comic in the space provided, as well as the names of anyone working on the comic book.
Select the layout for your comic book. You can choose how many panels to have per line and how many lines to have per page. If the website you are using doesn't allow you to choose the precise layout, you can simply complete the comic book by doing one line at a time and combining them in the end.
Add people and props to each dialogue box by clicking the design you'd like to use from the menu on the bottom of the screen and dragging them wherever you'd like. After you have completed a box, select which shape of dialogue/thought balloon you'd like to hover over the character/characters. Click to drag and position it above the character's head, then type in your caption.
Move on to complete each box for your comic book. When you are finished, click "Save" to save the comic book to your computer or "Print" to print out your comic book page by page.