The coil is the inductor part of an inductor-capacitor pair that is intended to be resonant at the frequency of interest. As an example, a 100 pf capacitor and 100 microhenry inductor should resonate at about 1700 kHz if I am reading the table right.
A coil is made up of multiple turns of wire, often on a form but a form is not required. More turns is more inductance so what is usually done is a coil is wound with maximum turns required then tapped so that less turns can be easily employed.
As a starting point a machine wound coil, 2 inches in diameter with 10 turns per inch will deliver about 25 microhenries - so a 4 long inch coil would give you about 100 microhenries.
Pair this with a variable capacitor from an old radio - might be 50 pf to 365 pf. That pair will give you coverage at the upper end of the AM broadcast band here in the US.
Advise if you need more info. I am sure there are good websites. I know National Radio Club has a lot of stuff like this. All of my info is printed in handbooks.