Hook up your red (+) wire first and then your white (-) second. The reason you see a few sparks fly is likely a draw is occuring (CO detector, mother board for fridge, loading the electronics for you entertainment system). Hook up and tighten with a wrench.
If you fear something happened after hooking up battery go inside to where your converter box is. On the left side are your breakers for 120 shore power. On the right are your fuses for 12v - if you see a light on by one of the fuses it will have to be replaced. Good idea to keep spare fuses: 5, 10, 15, 20, and 40 amp fuses are a good thing "just in case" and also good to help other campers out if and when they have 'issues.'