If you don't have NIH grants, and therefore do not have an NIH login, you can just use whatever My NCBI login you have.
You can access your My Bibliography from the username menu. Click your username in the upper right corner of any NCBI page, then click on "Publications". You can also see "My Bibliography" as a panel in your My NCBI page ("Dashboard" from username menu).
If you have been named a delegate for someone else's bibliography, it will also show up in the "My Bibliography" panel.
To manage your bibliography, click on the "Manage My Bibliography" link under your bibliography in your My NCBI dashboard page.
When you are viewing your My Bibliography page, if you haven't created your bibliography yet, just click on the "+ Add citations" menu near the top of the page.
To add citations to your bibliography, you can search PubMed for your manuscripts and add them. If you have publications that are not listed in PubMed, as well as other types of scholarly output, you can enter them manually using a fill-in form provided. Use the drop down menu in the "+ Add Citations" menu to add "Manually," then select the publication type from the manual entry panel's dropdown. You can also upload an .ris formatted file from EndNote or other citation management software.