I've recently gotten into binding fanfiction as real books! It's a fun way to participate in fandom and turn it from something you do only online into something you can do anywhere. I was reading a REYLO fanfic from a beautiful handmade book at work, and no one knew!
It's not a difficult process once you know how to do it. I will describe here the steps for my favorite way to make a hardcover book (sewn-board binding), and link some good resources for other types of bindings at the end. You can get incredibly in the weeds about all of this; grain direction, paper color, quarto/octavo, the best adhesive to use. It can be a lot. For example, at this point in your journey, if I tell you I love making cream color legal quarto sewn board bindings with a breakaway spine, if you don't know what that means, it's fine. To quote someone else in the Renegade Bindery, your book won't explode.
The advice I would give someone is to just start if you want to! I began by printing short oneshots and sewing them into pamphlets, like the old fanzines used to be. If you can read it and it has pages, it's a book! Don't let anyone tell you that your method of binding is less-than a different type. If your interested in learning how to make that style of binding, you can use the tutorial I learned from, here on Tumblr, by eat0crow.
Step One: find a fic! This is either the hardest or easiest part, depending on how many faves you have. A good length for a sewn board is about 50 - 80k words but run free. Make an anthology of 100 word drabbles. Live your freak.
Step Two: Open a word processor (aka your typesetting program). If you have a Microsoft Word copy, I highly recommend using that as you first start out. Blak Books Bindery has a Word Macro that will automatically do step two for you. If you are not using Word, you'll have to do this manually:
Set your page size to "statement" if you are in North America, and A5 elsewhere. Paste in your text from AO3 or FFN. Highlight all text and hit "justify," and remove space before/after paragraphs. Then, keeping it highlighted, make your indent style "first line" and however much you prefer. I do 0.19 inches. This should make your text look formatted like a novel; you can stop here, or go through and change fonts, margins, whatever you like. Margins should be slightly smaller than the standard for a full-size sheet. Definitely include page numbers. Otherwise, you have full control here; that's part of the beauty of DIY.
Step Three: Impose! Download as a PDF, and then upload it to the imposer, which is just a fancy way of saying "the software to make it look fucked up when I print so that when I sew it together it looks right." Once you've input your preferred settings, hit generate PDF and it will automatically download.
Leave everything alone except the following:
Printer: choose either Letter or A4, depending on how you'll print.
Page Layout: folio
Signature Format: Standard signatures. Go with 4 until you learn your preference.
Flyleafs: 1
Step Four: Print. You'll need to select "flip on short edge" in your printer settings. If your printer can't double side, you can do it manually, but you'll have to figure that out yourself. You now have a bunch of signatures that need to be folded. The sheet on top should have sequential numbers: that's the center of your signature. Take the three pages under it (if you chose 4) and fold them all together, making the two numbers on top 'kiss.' If you've done it right, you should have a mini booklet that has all the pages in the correct order, and the next sheet on your pile should have two sequential numbers on top.
Step Four: Make a punching jig. I just use a piece of cardstock the same size as my signatures, and mark where I want to stab. I recommend six holes. Take something stabby (a thumbtack works great) and punch those six holes out.
Step Five