Trickle Charger Questions

So I waited too long between drives on my '89 325i and now I've got a dead battery. I've got a trickle charger, but I want to ensure that I use it properly (last time I think it sent a power surge that made me have to reset my OBC--I don't want to take too many chances on that as one day the OBC may not reset).



I'd like to ensure that I'm doing the following three things in the proper order: (i) Thing One: Power plug from outlet to charger; (ii) Thing Two: Red cable to red terminal on the battery; (iii) Thing Three: Black cable to black terminal on the battery. In what order should I do these "things"? Am I supposed to hook one of the cables to "ground" instead of the battery (I never understood how this worked and I've never had trouble jumping a car based on hooking both jumper cables to the battery instead of one to the frame).



Also, my charger has a couple of options I can select with an old fashioned switch. I know I pick the 12V setting. I think I can also choose between more amps and fewer amps. Which amps should I pick when I don't care how long it takes to get a charge?



Thanks in advance for any tips/suggestions!!

Trickle Charger Questions