These are the items you'll need, 2 bar clamps, two wooden boards (old cupboard, get from DIY market, etc.) a preferably old brush and some glue (wood glue or specialized bookbinding glue)

Now straighten out your stack of paper, put it on one board lying on the desk, then very carefully put the 2nd board on the stack. ask someone to tighten the clamps left and right leaving about 1-1.5cm of space for the stack of paper.

This is to show the alignment of the paperstack and the leftover space over the board.

Macros are fun

and this one is to show you how to make it better... note the bad alignment of the paper.

To avoid having glue on the sides of your book wrap scotch-tape around the whole back of the book (vertically) to prevent the glue of pouring out.

This is roughly how it should look like when applied...

Now take a good load of the glue onto your brush and apply it to the back of your book. It should be well covered. Also note that pressing the paperstack downwards and upwards to make the glue go a little "inside" the pages can improve the results vastly. But be careful not to leave too much glue sticking to the tape to prevent "blobs" you'd have to cut off.

The first layer of glue applied

After waiting for the first layer of glue to dry apply some more layers to achieve a nice thick layer of solid glue.

Last layer drying

Now that the last layer dried take the book out of this a bit wild construction and cut two thick (>200g) papers to fit.

But before fastening front/back we need a solid spine. For this you need a piece of (80g) paper and some fabric (old textile shopping bag, whatever), about 2 times as wide as the back of your book (note: you can also use only the fabric without the paper if you prefer a fabric-looking spine). Glue the two together, apply some more glue to the bookback (only the back, be careful not to drip on the sides of your book) and apply the Spine you just made (paper/fabric should still be glue-wet)

Roughly like this, just without the glue drops on the bottom of the book.

This is how the front looks like with the spine applied.

Now that the spine has dried you can simply put some (not too much) glue on the front/back and apply them. Easy going .

A first test shows that it's ... a book! Congrats, you made it!

Also the thick layer of paint backed by the fabric spine the book is quite tough, here bended it like you sometimes do with commercially made books to make them keep open on a page, worked multiple times without any harm!