I am quite experienced with C++(programming for over 1 year),I know how to make CLI/Console Programs,but I cannot wrap my mind over GUI programming in C++,Every library I've seen so far sucks or is ugly as heck,can anyone recommend me any library(cross-platform or not),which is legit standard C++ code?
I would also suggest Qt because it is open source and cross platform. It also has a great team behind it and it has a great GUI designer. An example of where Qt is used is in KDE which is a linux desktop environment(one of my favourites).
I believe as of now there are not many(if any) Qt5 beginner books so you will have to read up on it on their site though they have so many tutorials and it is very friendly.
Something to get started: http://doc.qt.io/qt-5/gettingstartedqt.html