How do I use Lidgren.Network? I mean, "install" it so I can use it in my project? Because I would love to get started with simple multiplayer games, but I can't find any good tutorials online, but I've heard that Lidgren.Network is good :D
I tried to just drag the Lidgren.Network into the project, but I couldn't use it that way, I guess it was a really bad idea..
And also, if I make a game using Lidgren.Network for networking, will I be able to sell it? And if not, will I be able to upload it at all?
You need to add the Lidgren.dll
as a reference to your project. Take a look at the picture below (Made in VS 2012, but same for any other editions)
Hit browse and find your Lidgren dll.
This is not the place for legal advice, so don't tank us in the place of a lawyer, but as you can see on the homepage, it is under a MIT license.
... including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software...