Quill pens have been around for hundreds of years. Two centuries ago, every schoolchild knew how to make and use this simple tool; now only a few re-enactors, role-players and the romantically-inclined are so learned. Although it is arcane, it is quite easy.
The feathers used to make a writing quill are usually goose or turkey quills. Chicken or other small birds have quills that are too small with too thin a shaft. You can buy goose quills at craft stores or online. Buy a dozen or more, since you will spoil a few while you're learning how to use them. While at the store, select those with the widest shaft because they hold a greater supply of ink. Reject those with crushed or bent shafts; you won't be able to use these.
Once you get the feathers home, your first step will be to 'temper' them, or heat-treat them so that the feather shaft becomes harder and less easy to crush. Put a can of sand into your oven at 350-375 degrees and leave it until the sand is hot all the way through. Then take the can out of the oven and stick all your quills, point down, into the sand as far as they will go. Leave them there until the sand cools. Now the feather tips are hardened and ready to cut.
A sharp paring knife or an exacto knife can be used, but of course a 'penknife' would be perfect, if you have one (and now you know where the name came from). Cut the tip of the quill off, along a diagonal. You may want to make some additional cuts, one long but very shallow and the other, closer to the tip, shorter and a little deeper. You now have a tip that comes to a rounded point. Split the point with your knife, and carve out fingernail slivers on either side of the tip to exaggerate the point. It will look like the tip of a fountain pen - your quill is ready to use.
Keep your knife handy, however; you will have to resharpen the tip every two-three pages or so. If this seems too labor-intensive for you, you can purchase ready-made quills with metal nibs on the tips that never need sharpening; they're less authentic, though, and anachronistic, if you're a re-enactor.
You will need ink that is dark and thin. You can purchase ink specifically made for 'dip pens' which works perfectly. You can try art-ink, which may be too thick, depending on the manufacturer - a thick ink will glob onto the nib and make blobs on the paper, which can become very frustrating. Or you can make your own ink using a Chinese ink stick and grindstone such as is used in Oriental brush-painting (sumi-e) and calligraphy. The advantage of the latter is that you can grind the ink as light or dark as you like, and one ink-stick can last a lifetime.
Since you've hand-made your pen, and maybe even your ink, you might be tempted to use it on some of the lovely hand-made papers that are now available. Resist this impulse; hand-made paper is far too rough and porous to use with a dip pen. One touch of the pen on the paper and all the ink will be sucked out into an ugly blot. You want to use paper that is very smooth, almost shiny, with a 'stiff' finish. The pen will glide across a smooth surface, leaving a lovely trail of ink behind. Try colored inks; violet or burgundy can create quite a dramatic flair. Faux parchment can be good, but you will have to watch your touch; since it is slightly rough, the nib can get stuck in a tiny crevice and then snap out, leaving a spray of ink behind. Cheap school binder paper is actually quite ideal for writing with a dip pen, although you may find the ruled lines take away a lot of the romance of it.
Now you're ready to write the Great American Novel, or at least make journaling a special occasion.