I recommend getting a test prior to adding because as Jason says people rarely have no salt at all.
Then put that result in the Now column of the pool calculator. I've read that the target should be around 2000ppm for the 'feel good' aspect, so put 2000pppm in the target. It will tell you how much to add. Make sure all your gallons, etc are entered properly.
My initial test was off (of course! pool store) I have a bit more than 2000 but it will go down over summer.
I just dumped the bags in while I was in the pool, walked around and stirred it up really well and that's it.
I can taste it, but it's not strong like gargling with salt water or when you are in the ocean. And, the water has a clarity and shimmer that is definitely different.
Question does/or did it change any of your chlorine/or and other chemical levels ? Should I watch and test for anything after adding salt other than salt