If you drive for business and don't receive mileage reimbursement from your employer, then you may be able to deduct the standard IRS mileage rate (54 cents per mile as of 2016) from your income taxes as a business expense. In order to do so, however, you will need to keep a log of all of the business-related miles that you drive.
Printable Log for Tracking Business Mileage
According to IRS Publication 463, you must keep "timely and accurate records" of business mileage. A daily log is appropriate for this purpose. The daily mileage log template provided here is a good option for IRS mileage recordkeeping. To access the template, click the image, and the form will open as a printable PDF document you can print and/or download. If you need assistance accessing the document, see this guide to adobe printables.
Keep Sufficient Records of Business Mileage
When tracking business mileage, it is important to keep adequate detail specific to each business outing you make in your car and to record business-related car trips on a daily basis. As has been indicated by tax court decisions such as Royster v. Commissioner of Internal Revenue, your business mileage records must substantiate when you traveled, where you traveled and the business purpose for each trip. This information is necessary to back up the amount you claim as a deduction for business mileage. If you opt not to use a mileage log, you could use a similar method, such as an account book, a notebook or a diary - as long as whatever method you use has sufficient detail.