What business or corporate expenses can I deduct?
The IRS uses two rules for determining if an expense is deductible- in general, you may deduct ordinary and necessary expenses for conducting a trade or business. An ordinary expense is an expense that is common and accepted in your trade or business. A necessary expense is one that is appropriate for the business.
Vehicle expenses and home office deductions are often overlooked. However if you travel to WalMart to grab some copy paper, you can deduct your miles in conjunction with the operation of your business.
If you use a dedicated room in your home to manage your business you can deduct that as well- it gets a bit tricky if you have another office. You must perform substantial managerial activities in your home office for it to be considered your primary office.