for Load Testing/Performance testing first you need to know 
the objectives of testing, what all the business 
requirements in terms of response time which is a user 
concern, throughtput which is a business concern, resourse 
utitlization which is a system concern. These three are the 
main constraints. Then knowing the entrance criteria and 
exit criteria for performance testing. Various types of 
tests such as smoke test(initial test for performance test. 
If the application passes this test, then undergoes the 
remaining tests), capacity test, reliability test, 
endurance test, spike test, stress test. Then regarding 
tool you should know the components of the LoadRunner such 
as VuGen(how to create scripts, parameterization, 
correlation), Controller(creating scenarios, assigning 
vuser to loadgenerator, running them), Analysis(making the 
reports by seeing graphs and records)

thanks rani 

can you help topic wise