It is best to email the rightsholders, as it is quicker than faxing or posting a letter to them. Check the Web for contact details for publishers, if it is not available on the publication or work you wish to copy from.
When writing for permission, give the full bibliographic details of the book, journal, etc. (i.e. author, title, chapter or article title, volume number, issue no. date, ISBN or ISSN numbers, country of publication, etc.)
Explain why you need permission. If it is for research or educational or non-commercial purposes, state this and stress that it is not for any commercial gain. If it is to be included in a publication, CD, DVD, etc. for commercial purposes, tell them, so they know how their material will be used.
If they respond with a charge, you will need to decide whether you want to copy the material or not. If the fee is reasonable, arrange to pay it. If not reasonable, try negotiating a better price with the rightsholder.
If you do not receive a response, do not assume that permission has been granted. You need written permission before going ahead. If you have tried a number of times and still get no response, but absolutely have to use the material in your research or book, then you will have to decide on the risk involved if you do use it without permission. You may consider including a notice in your work stating that you have tried several times to get permission but am not able to trace the rightsholder. Then invite the rightsholder or anyone who knows the whereabouts of the publisher to come forward to discuss the payment of copyright fees. Alternatively, try finding similar material that is free or out of copyright.