I made one for use at our church. It was a fun project. I have some (very amateur) book-binding knowledge, which mainly helped with the leatherwork and knowing where to find stuff. (But even the first time ever that I put leather on a book it came out OK.)

Procedure:

1. Buy a binder with a quality mechanism and hardboard sides (doesn't matter what they look like). (At one point I entertained the idea of just buying the mechanism, which you can get for very little money, and providing my own hardboard sides -- the material to do this is called 'Davey board'.)

2. Cover with leather or bookbinding cloth. It's basically like wrapping a present (part-way). There are youtube videos a-plenty on this part. If you want to get fancier, cut 4 or 5 short strips of leather and glue them across the 'spine' (perpendicular to it), and when you cover them, it will look like the stitching in a traditionally bound book. (Those who don't like 'fake' stuff will not appreciate this step, to be sure, but they might also be surprised to learn how many books have this fake stitching on the spine.)

3. Get yourself some nice handmade marbled endpaper (or make it if you are ambitious -- again there are plenty of instructional videos if you have the itch to make it yourself, which is a very very cool project, especially with kids). Cut the paper (cutting it exactly to size and exactly with 90 degree corners is actually one of the more challenging aspects of this project believe it or not, and you should definitely use a paper-cutter for it, not scissors) and glue it to the insides, overlapping the leather (or cloth) by a 1/4 inch or so. Resist the temptation to use spray adhesive. If you can use a brayer to spread the glue thinly and evenly, so much the better. Examine a well bound book to see how it should appear.

4. Optionally, add some decoration to the outside. I ordered a metal stamp in the shape of a nice-looking cross from Etsy and used it to stamp a gold-foil cross on the front cover. (I don't have a hot-stamp machine but experimentation with a blowtorch and a clamp did the trick. I am still learning how to do real gold foil on books, and don't yet trust myself to do it for public consumption. Maybe someday. It is an art that takes practice.) The stamp was not cheap ($40 I think?) but it is of course permanent. The gold foil (comes in a roll, made for a hot-stamp machine) is just a few dollars for a lifetime supply.

That sounds like a lot, but you can really make it as simple or involved as you want. There are hundreds of instructional videos and (gasp!) written documents (books in libraries, even, if you can imagine) on how to do each of these things in a 'traditional' way, and also in various 'crafty and relatively easy' ways.

For supplies, I like to use Talas (no association -- the link below takes you straight to their marbled papers):

http://www.talasonline.com/decorative-papers

but there are plenty of other places. If you go a more 'crafty' route (such as would be done by 'scrapbookers' for example) you can pick up what you need at your local craft store, and you can get quite good results.