Have your idea ready. Write some passages on paper and get ideas as to how you would like the pictures to appear in the strip. Comic strip sizes for newspapers range from 4 1/16 inches by 13 inches. Sunday comic strip large sizes are 5 3/8 inches by 11 1/2 inches and smaller ones run 3 3/4 inches by 11 1/2 inches. You are not bound by these dimensions. You can make them any size you want to fit your vision.
Make pencil sketches of your ideas. Leave room for text if you desire.
Ink the sketches once you are satisfied with your pencil drawings.
Print your comic strip book. You have many options. You can submit to publishers, but you may want to go the self-publishing route. Sites like Marvel's Superhero Squad let you create your comic strips on their website. You may also want to look into print-on-demand sites like Lulu.com and CreateSpace to create your book. These sites let you customize your insides and covers for free and all you have to pay for is copies.
Once your comic strip book is made, you can advertise it through comic sites or sell it on sites like Amazon. Self-promotion takes a lot of work, but if you want a comic strip book for your own pleasure, these steps will get you there and you can share your work with family and friends.