I am totally new for UML and what to learn it. I have searched for many resources to learn UML including videos, tutorials etc but none of them are illustrative. The word illustrative means here is resources from which I can learn basics of UML notations, how to merge them to draw diagram, how to construct various diagrams, efficient and free tools to develop make diagrams.
It will be very helpful to suggest any book or tutorial which can help to learn UML efficiently.