In this article we are going to see very simple steps to perform load test on a site. For basic idea about jmeter, please see my this post.

Step 1 : Download latest JMeter from this link 
Step 2 : Extract and Run jmeter.bat from bin(my case, C:\apache-jmeter-2.8\bin)
Step 3: Add thread group and provide some user , time and loop counter(I use 10 user, 2 second and loop count 3). Here we have to use as for requirement. Suppose, Client want the load 1000 user. So, for that if we have very fast PC, we can use 1000 user in 1 second. But it is better to increase the number of user with little more time which creates less load to the PC. In this case , 1000 users in 10 seconds.

Step 4 : Right click on Thread group and add a sampler "HTTP Request"
Step 5 : Provide the link of your site.( I use for test) as server name
Step 6: Right click on Thread group and add some Listeners (to view report).
I have added
View Results Tree
View Results in Table
Graph Results
Monitor Results
Aggregate Report
Comparison Assertion Visualizer
Response Time Graph
Summary Report

Step 7 : Run the test. 
You can see/save the report and get you test done