Writing-related clipart is sometimes used by teachers, students and writers in different projects. If it is just one image you need you might be better off trying to draw it yourself or find an artist friend. There are also many clipart sites with lots of images of pens, pencils, typewriters, etc. Be sure to read the terms very carefully and make you have the right to use any images. Here are some clipart resources that contain writing clipart.

Classroom Clipart
This site offers clipart designed for classroom, including books, pencils, etc. They charge an annual license fee.

ClipArt Etc.
ClipArt Etc offers over 71000 clipart illustrations designed to be appropriate for classroom use.

Clipart.com
Clipart.com has hundreds of writing-related cllipart images and stock photos. They charge a subscription fee.

Clker.com
Clker offers free clip art that is shared by different users and sources.

Draw a Pencil Videos
You can also learn to draw your own pencil. There are many videos on YouTube that will show you how.

Graphics Factory
Graphics Factory has over 800 images tags under writing. The site charges a membership fee.

iClipart for Schools
iClipart has a special site for schools that contains school, reading and writing images. They charge a subscription fee.

iStock
iStock charges per image and offers clipart and photos. Images include typing, books, typewriters, writing illustrations and more.

MyCuteGraphics
MyCuteGraphics offers cute original clip art that includes pencils, books, reading and more.

Shutterstock
Shutterstock is best known for carrying photos but they also have a big clipart section that you can search for writing-related clipart.