build job: JobB, parameters: [string(name: 'PARAMETER_NAME', value: 'PARAMETER_VALUE')], wait: falseThe 'wait' parameter indicates if you want JobB to finish before JobA does (true), or JobA to finish even before JobB does (false).
Jenkins has built-in environment variables that you can pass around between jobs, or you can pass any of JobA's variables to JobB.
Chris