Car wont start - help!

[tamo300]

Thank you very much indeed for all of your help - it's really appreciated.

I have purchased a booster pack to charge the battery. I was wondering what the following means on the booster pack instructions) attach the red cable to the positive on the battery - this i understand - BUT what does it mean when they say attach the black to an EARTH POINT on the engine - attach it to a non-moving metal part on the engine?...i'm a bit confused........or can I attach it to the negative on the battery? (the booster manual says not to but attach the black to an earth/metal point)....

...also, in the Yaris manual it says that when recharging the battery whilst still in the car, the GROUND CABLE has to be disconnected....um, what is this ground cable, and do I reconnect it after the booster has recharged the battery?