The magnets I fish with are Neodymium magnets, a part of the rare earth magnets. So how to make Neodymium magnets you ask?
Well, you take som neodymium (Nd), some iron (Fe) and some Boron (B). These three elements are then melted in a furnace and gets the form Nd2Fe14B. When they have been melted together and cooled down, they are pulverized and milled. The powder is then heated and compressed into blocks which are afterwards heat treated. Hereafter the neodymium blocks are cut into shape, then surface treated (So we can throw them into the water) and then magnetized with another magnet. In this process, it is the neodymium which makes sure the iron and neodymium solution stays a permanent magnet. 
After this step, I guess they are glued on the mounts we use for fishing with the magnets, and hereafter they are ready for shipment to us.

In the pictures, the magnet part is the inner part on the picture to the right.  The outer part is the mount mentioned above.

So I was scrolling through the subreddit, magnetfishing, find it here, and I found an interesting link. A guy has assembled a long list of every link you have to know to start magnet fishing, where to buy the magnets, where to, where to find instructional videos, where to find magnet fishing videos, Imgur magnet fishing posts and a lot more. It is a really cool list, and you can find it here:
http://losingmyconnection.de/magnet-fishing-link-list/

Of course I was a little proud when I saw, that this page was on the list as well :-)

Hey Guys

Just wanted to tell you about the subreddit magnetfishing

https://www.reddit.com/r/magnetfishing/

There are a lot of interesting pictures, videos and discussions in there, so give it a look