Staff paper!
Once you've chosen, you take a sheet of paper and -- well, you know the song... YOUUUU MUST RIP IT!
Now we collate them into signatures. For this weight of paper, I used 8 folios/signature, which makes mini-"books" of 16 pages. Just stick one folio inside another, and if you have fuzzy edges, it works best to alternate "left" and "right" folios.
Once you've made 6 signatures, you can put them together into a block. As you can see, that wavy edge-pattern you've seen on some old books is due to the folios being collated after the paper was cut.

...Of course, you can't make these stay together until you've punched holes through them, which was the secret catch to this post. Oh man, you'll have to take another ten minutes now. I win!!
Sew anyway...
Then you sew them together. On this one, I forgot that one is meant to punch four holes, rather than three, but it still worked... just won't be as even.
So now you've got your signatures all sewn; you do still need to smear glue on and near the spine, then press cheesecloth (or gauze, like I use) into the glue, to hold everything together nice and firmly. Leave this assembly pressed between a rock and a hard place, and move on to the cover.
And once you have that, it is time to take over the world. And/or make some endpapers. And find something to cover it with. Part II to come soon!
P.S. I made more tarts this morning. <3