I am going to dive in more serious and complex application development and for that; I need some specific approach to get reliable results. I found the answer, is UML (Unified Modeling Language).
I am really interested to explore about but don’t know where to start. It is very dense area and it is extremely easy to lose in various types of different shapes defined by UML. While my research, I found an excellent guide for UML to start from. Here it is. It is a great start for beginners.