If you live locally, see Don Bray's post below. I would caveat what he said by pointing out that you can take a picture of the deed books for free instead of taking the time to break the book down and making a copy on the copy machine of each page. Instead, I would have the clerk make a copy of the index to Section 25-6N-6W and keep that for your records.
If you do not live locally, call the clerk's office and ask how many pages are in the index for your section and the cost for a copy of the entire index. Send a check and a prepaid envelope with your return address and enough postage for the clerk to send the index back to you.
Next, soft chain the title backwards from your interest by annotating the instruments you will need to chain your title to the original land patent.
Review what instruments that you can online on Idoc. For those that are unavailable online, I recommend that you either repeat the earlier process for obtaining copies or you can post on the forum and hopefully someone in the area may be able to pick them up for you when they swing by.
When it comes to chaining title, you will likely have many questions. I would be happy to answer your questions over the phone and I am sure the forum would also assist. If you send a friend request I would be happy to send my contact info to explain the process over the phone or in more detail over email.