Thanks for the help. Is there anything else I should know before I continue with GLFW 3.0?
Not really, just make sure to work on most recent source and keep in mind that API still changes so you may find yourself in a situation where some function name was renamed.
Also, is it possible to use two libraries at the same time? Say SFML 2.0 and GLFW 3.0? Are there any advantages to this?
Not sure if its possible, but its rather pointless as these two libraries have duplicate functionality. Both are used to create GL context, but SFML offers much more (just check the site for all the modules it has). GLFW is solely focused on getting you a GL context and handles events in a created window(s). It does nothing more, which is nice if you want to do things yourself rather than rely on a big library to do everything for you (SFML).
If you really want to learn OpenGL I guess its worth going minimal and learn the basics rather than have a library do it for you (SFML has GL wrappers for most functionality so you can work with it without using the low level API at all).