1) it is optional, not required (the ProQuest deposit is required); and 2) it will be available to everyone on the Internet; there is no embargo for dissertations in the UNL DigitalCommons. Master's candidates: Deposit of your thesis or project is required.
(If an embargo, restricted access is necessary, you may deposit the thesis at /embargotheses/ — but only after getting the prior approval of your department and the Graduate Office; contact Terri Eastin). All depositors: We try to observe a 24-hour "cooling off" period to give you opportunity to correct those "oops" issues that seem to emerge just after deposit. Upon deposit, you will immediately receive an email that your submission has been received (and this is what you need to show the Graduate Office).
However, you can still log back in and select Revise and upload a new version with your advisor's name spelled right, or your mother thanked in the Acknowledgments, or whatever you're stressing about. After about a day, your submission will be "published" or "posted", making it available to the Internet; you will get another email to that effect, and your submission can no longer be changed--by you. If further changes are needed, these can be made by sending a revised file to the administrator requesting replacement of the current online version.
That creates duplicate records, confusion, wasted effort, frustration, sadness, tears, and causes kittens to get sick. Click the "Submit your paper or article" link at the bottom of the gray box at left. You should be able to copy (Ctrl-C) and paste (Ctrl-V) most fields.
You are the sole author; your advisor is not considered a co-author. Your institution is "University of Nebraska-Lincoln" (not "at Lincoln" or ", Lincoln"). Do not leave it blank; then the administrator has to fill it in, and he is tempted to make it something silly.
You do not need to repeat your name and title in the Abstract field; just the body of the abstract. When you reach the question "Was this submission previously published in a journal?", just skip that part. Be sure to click the "Submit" button at the bottom.
Files upload at the rate of about 5 Mb per minute, so if you have an ungodly large file, it may take a bit of time. If your file exceeds 40 Mb, think about reducing its size--there are many ways; Google "reduce pdf file size" to find some.