Lets start by starting up Selenium IDE. This can be found under the tools menu in Firefox.
When the has been started it will automatically recording. Now that we have this lets start playing around.
The next task that you should try is create a script that checks that certain items are on the page. This is definitely a time for testers to use their own intuition on what should be checked and what shouldn't.
Note: Don't try and verify/assert the whole page. If you do your script will run very slowly especially if you start using xpath to specify where the element is.
I have created a more substantial script for you all to use here.
Lets start to create a test suite using the new functionality of Selenium IDE 1.0+. A test suite allows you to group test cases together. This is quite useful when testing behavioural areas. To start creating a test suite all you need to do is click on File > New Test Case. The IDE will create the test suite with your finished test case and a new test case.
You will need to make sure that you save the test suite. If you forget to do this you will lose you test suite and will have to create one with new test cases. You will then have to hack it to get your test cases into the test suite.
Once you have had gone through it yourself try do the same basic thing with your own websites