They are intendin on making the mods easily available through the game self but since its still alpha that is not yet implanted so that is a plus for lazy people like you (and me).
For as far as i know they may want to make it even more simple to mod basic things like items in but for now it is good doable even if you have no knoledge at all.
The game provides all its files so a lot you can copy past and change the names. And since every normal file is accesable you can alway look at the files and see how they did it.
Creating an item and making it craftable and placeable is quite easy.
Here are a few topic how to start modding an modding faq.
Sublime text editor is real nice to edit the files. And jsonlint is a sit to validate your .json files to see if there arent any mistakes.
And the first few items take some time cause its new but after that it is just a matter of repeating a few simple steps.
And concering installing mods. Dowload the mod file and locate where your stone hearth is instaled (with steam you can rightclick and there is an option wit local files) and open the mod folder and just place the downloaded mod file in there.
I didnt know which of the 2 you meant so i gave you both ^¢^