The single most important thing you can do is check the copyright agreement BEFORE you submit your manuscript.
However, it is well worth your time to check out the policy from the onset:
Investigators must retain the right to deposit work in PubMed Central.
Make sure that any copyright transfer or other publication agreements allow the article to be submitted to NIH in accordance with the Policy. For journal policy information, see SHERPA/RoMEO (http://www.sherpa.ac.uk/romeo.php), or contact library staff.
Investigators may need to amend copyright transfer agreements at time of manuscript submission. NIH advises authors to work with the publisher before any rights are transferred to ensure that all conditions of the Policy can be met. NIH cautions authors to avoid signing any agreements with publishers that do not allow the author to comply with the NIH Public Access Policy.
Template language is available to help assure copyright agreements enable compliance. MU Administrative Services and the Office of the Provost have endorsed the use of the SPARC (Scholarly Publishing and Academic Resources Coalition) Author Addendum available at:http://www.arl.org/sparc/author/completeonline.shtml
Many journal publishers allow you to archive your work in your institutional repository.
In addition to making sure your NIH-funded research is deposited in PubMed Central, submit it to MOspace: Institutional Repository as well!
Why submit to MOspace: Institutional Repository?