How to run Selenium test cases using RQM

I would start here:
Running JUnit Selenium adapter execution tests

There are four sub topics on this page that should be helpful as well (The links are accessible from the page above)

Configuring JUnit Selenium adapters
To implement a JUnit Selenium adapter, you must first configure it.

Starting JUnit Selenium adapters
After you configure the JUnit Selenium adapter, you can start the adapter from a command prompt for the first time.

Creating and running Selenium scripts in the Quality Management application
You can create a reference to a Selenium script just as you would create any script in the Quality Management application.

Adding screen captures created by a JUnit Selenium test to execution results
When a JUnit Selenium test is executed it can create screen captures of the browser session to show error conditions. You can include these screen captures in the execution result of the testcase or testsuite run for later viewing.