[Updated 2013-01-09] In a business contract, your signature block should make it clear that it’s your company, not you personally, that is "signing."
(This assumes, of course, that your company is in fact a corporation, LLC, or other entity that keeps you from being personally liable. If not, that’s definitely something to bring up with your lawyer.)
The simple, unadorned signature block above could result in your being held personally liable for the contract obligations.
John Doe, Vice President,
In the above example, including your corporate title in your printed signature line might not be enough to save you from personal liability: A court could find that your title was merely a statement of identification, and not an indication that it was ABC Corporation that was signing the contract instead of you personally.
by: John Doe, Vice President
John Doe, Vice President
Ask your lawyer if you have questions about what form of signature block is appropriate for your situation.
[ADDED 2013-01-09:] Brian Rogers goes into detail about how various types of business entity should sign a contract in his blog post How to Sign a Contract (Jan. 8, 2013)
For more examples and tips, see my e-book, Signing a Business Contract? , an annotated checklist for business people, with tips and true stories to help you steer clear of various possible contract minefields. Learn more ….