general questions

[Rizwan Khan]

Hello,

I have few general questions regarding Linux:
	
-How can i check my system log, i.e. how many users logged in my
system, which application they have used,
-Status of each application, whether its running or not and its log,
-If any of application crashes while it was running, how i can check
the reason, i mean is there any such system log which can tell the
reason why it was crashed,
-How i can check that how much system resources are being consumed any
any specific application,

Thanks!!

-- 
Muhammad Rizwan Khan