Use this site to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
Did you publish a paper at a conference? as an article in a journal? Were you a co-author on an article that contained information you are now including in your dissertation or thesis? You MAY need to get permission to reuse any substantial portion of that article or paper in your dissertation or thesis. Why? Because you may have signed a contract that gives your rights to the society, conference host, or publisher.
Can you post the final edited PDF on your web site?
Can you deposit a copy of the article in the required public or university repositories (like PubMed Central)?
Can you use all or part of the article in your thesis or dissertation? With or without permission? (Keep a copy, you'll need it when it is time to deposit a copy of the thesis or dissertation with ProQuest, a requirement for graduation.)
Is there an "open access" option? With or without additional fees?
Most publishers require you to sign a contract that gives the publisher ALL or some of your copyright. Some of the issues may be negotiable. Many are not. Open access might be possible, often with an additional author fee attached. Below are some standard "contracts" that might be of interest to you as you decide where to publish your research.
If you reuse information from a previously published article, conference, book, thesis or dissertation you MUST provide an appropriate citation. If you don't you may plagiarizing yourself. Most publishers require you to sign a document that your submission is original and has not been published elsewhere. Within a thesis or dissertation you need to acknowledge if or when substantive portions of your writings have been published elsewhere.