If a taxpayer has one or more regular work location located away from their residence, the taxpayer may
deduct daily transportation expenses incurred in going between the taxpayer’s first business location
and a subsequent or temporary work location in the same trade or business, regardless of the distance.
If a taxpayer’s residence is the taxpayer’s principal place of business, the taxpayer may deduct daily
transportation expenses incurred in going between the residence and another work location in the same
trade or business, regardless of whether the other work location is regular or temporary and regardless
of the distance. This rule does not apply if traveling between your home office associated with one
business to a work location associated with a different business.
If you use part of your home for business, you may be able to deduct expenses for the business use of your home. These expenses may include mortgage interest, insurance, utilities, repairs, and depreciation
"You may choose any recordkeeping system suited to your business that clearly shows your income and expenses. Except in a few cases, the law does not require any special kind of records."
"You should keep adequate records to prove your expenses or have sufficient evidence that will support your own statement. You generally must have documentary evidence, such as receipts, canceled checks, or bills, to support your expenses. Additional evidence is required for travel, entertainment, gifts, and auto expenses."