Hello.
I am new to the world of open source so please answer accordingly!
I have seen many licenses in use, like GPL, MIT, Apache license. Of course I don't want to be a lawyer, but having at least a basic knowledge of all these would be helpful.
So where do I start? Do I simply read up these licenses? Or is there a book/ website out there that explains all this?
While it's probably not going to help much, I recently had a look at the page Open Source Licenses by Category over at www.opensource.org. Take a look at the category "License that are popular and widely used or with strong communities". I think that would be a good starting point.
While you'd probably have to be a lawyer to really understand and know all implications of every license, you can grasp the main differences by looking at them. Not all license texts are as long as that of GNU's GPL, so don't be afraid to look at them. (The MIT license is a good example. You can read it in about 1 minute's time.)
(The GNU GPL, btw., is considered by some to be the most restrictive open-source license, when it comes to using software in a commercial product. I think that was the initial reason why they came up with the GNU LGPL.)
Some more pointers to other questions here on Stack Overflow: