R50 cooper '04 not starting

[southendpier]

I had a flat battery on a R50 cooper. 04 plate. The starter wouldn't turn when trying to jump start and a new replacement battery has not worked. Key turns in barrel and all lights come on. When try to start the starter motor doesn't turn at all and I can simply hear a click or two from the engine area.

I'm not not great with cars but any idea what should I check first? Anything simple?

thanks.

[Smiljan]

The click could be either the starter relay or if louder click, click, click noise just the starter solenoid working but not passing enough current to the starter motor.

The connections on the starter are probably either loose or rotted. I'd start with getting the car up off the ground and checking the starter motor connections, make sure they're all in good condition.