I have been doing various forms of postgraduate study for a while now and yet there's still one problem which presents itself which I'm too embarrassed to ask my colleagues. There are a vast number of unedited manuscripts out there. Some are thankfully mentioned in catalogues, but it isn't always clear what they actually deal with.
I spend hours trawling through footnotes, bibliographies and catalogues that it seems I'll never stop, and along the way I gain the sense I'll never find anything original.
How do you, as historians, go about finding the resources that you need?
Edit: I intended this as a rather meta question about research methods, but if it isn't suitable for this subreddit I do apologise.
Not certain that this post will stay up, as it's not really a question about the human past or a meta-question about the /r/AskHistorians. But here's a reply anyway, because it's worth talking about!
I'll never find anything original
Not true! Here I'm assuming by 'original' you mean something which has received no scholarly attention. You'll be hard-pressed to find much untreated material in footnotes or bibliographies, as manuscripts generally show up there when they're being treated. Catalogues are a different story, but it can be difficult to know how to distill what you're reading into something useful. If your driving goal is to look at something as of yet untreated, printed materials like these will be difficult.
At the end of the day, you will want to get to an archive. While there are a good number of resources being digitized these days, some of which have not been treated (the ones I know best are early modern, unfortunately), the greater share have been in some way accounted for. Getting to an archive is your best bet, but you will face challenges depending on geography. If you are based in North America, for example, there will be significantly fewer unexamined medieval holdings than if you were based somewhere in Europe, where they didn't have to travel in the same way. That's not saying there aren't unexamined manuscripts elsewhere, but your odds are better in the areas they accumulated.
There are two steps I can recommend you. First, talk to an archivist. Ask them if there's anything they know of they'd wish someone would take a look at. While learning Middle French, I came into a conference paper this way: I asked an archivist at a nearby institution if he had anything interesting in Middle French he wished someone would examine, and it just so happened he did! Through my work, he got to know his holdings better, and I got to practice my languages and write a paper.
The second step is to find a topic which interests you and read deeply in the literature until you figure our where the primary source material is originating. Sometimes, this is easy: most information about medieval Bern will be in Bernese archives, for example. Figure out where people go to research a topic and then go kick around there, if you can. Chances are, either through talking with the archivist or digging for yourself, you'll come across something of interest.
Like I said, all this can be hard to do from a distance. If your interests can stretch into the early modern period, I'd be glad to point you to some digitized manuscripts, many of which have seen no work. As a bonus, most of them are printed! So much easier on the eyes...
Unfortunately, the above is personal experience, which is a mediocre source. In the interest of maintaining decorum and citing some sources, let me add a resource of two:
AHA Resources for Historical Research
A Survival Guide to Archival Research
Using Archives: A Guide to Effective Research by the Society of American Archivists