Thanks for the answer.
Can you explain or provide a link that explains better when it is legal to use a trademark?
For example, in writing are you allowed to use the term "McDonalds" if you are selling the book?
You may want to go to the United States Patent and Trademark Office website,
http://www.uspto.gov. The "fair use defense" under trademark law can be found in the Lanham Act, 15 United States Code, Section 1115(b)(4).
Please note that "fair use" is a DEFENSE to a trademark infringement claim and NOT permission to use a trademark. A court is the ultimate decider as to whether a use is fair or not. Please also note that "fair use" under trademark law is different than "fair use" under copyright law.
You are (generally*) safe using a trademark in a
descriptive way. For example: You can say, "He is drinking a Coke," "She is driving a Ford," "The girl saw Mickey Mouse at Disney World," without infringing on the Coke, Ford, or Disney trademark holder's rights.
You are (generally*) safe using a generic word at any time, even if the generic word is also used as a trademark. For example: You can say, "My mustang is not as pretty as my stallion," "My clean dishes are a joy," without infringing on the Mustang and Joy trademark holder's rights.
You are (sometimes*) safe using a trademark in comparative advertising. For example, you can say, "Twenty people taste-tested the two sodas and preferred Coke over Pepsi," if this is true. What is vital in compartive advertising is that any and all claims made about a trademarked company, product or service must be PROVABLY true.
You are (usually*) safe when using a trademark in any journalistic account. For example: "Police determined that the Ford Mustang parked outside Pizza Hut belonged to Detroit mayor, Dave Bing."
And you are (sometimes*) safe with parodies involving a trademark. Do an internet search of Weird Al Yankovic to see how he avoids lawsuits over his parodies by getting permission from rights-holders, even though parodies (good ones, at least) are often considered a fair use of copyrighted and trademarked material.
You generally cannot use another's trademark in a commercial manner without permission (with some exceptions as noted above). You cannot profit off another's trademark without permission. You cannot confuse consumers into thinking your company, product or service is sponsored by, endorsed by, affiliated with or connected in any way with another's trademarked company, product or service, unless it is in fact sponsored, endorsed, affiliated or connected with the company, product or service - at least, without good risk of an infringement suit.
*It is important to note that a trademark holder can sue for any reason at all or no reason. No use of a mark will be 100% safe unless you get permission from the trademark holder to use the mark in the way you intend prior to using it.
For the specifics on your book/method DVD, I recommend you check with an attorney in your area. All facts and particulars must be personally examined to determine if a use of another's trademark is permissible or not. Getting permission is always wise.
