I need some tips or samples to help me to implement use case diagram and sequence diagram. Such as which class I should inherit to show a use case shape? what these steps to implement a sequence diagram, I mean what properies, events, virtual methods I should use.

I know this is a big question, but you just need tell me some tips, do not have to give a complete answer. I already finshed a class diagram, so I know some thing about this Lib, I just need some tips.

Thanks a lot.