The best thing for coralline is not much different than any other CaCO3
animal in the tank. Proper chemistry; alk
and med-high lighting but with the coralline it will do better with an emphasis on the actinic photoperiod. Maintaining the chemistry at least in the beginning will be easiest through weekly water changes. The rock needs nothing special other than what I've mentioned. That and time
As the tank progresses you may wish to look into alternate methods for maintaining the chemistry but for now they should not be needed.
If you do not already have the pink/purple coralline on the rock you will need to seed it from an outside source. This can often be done by adding some sand from an established tank, purchasing some small rock that contains the coloration you want or possibley some Garf Grunge.
Once in the tank, all you need do is keep the chemistry in line seed the rest of the tank with coralline by sporing the water column. Turn off the skimmer when doing this and then gentley scrape or brush the coralline that is there and it should eventually spread. Leave the skimmer off for only a few hours to allow the coralline spores to settle out onto the rocks and such. If you are the patient type, simpley placing the coralline encrusted rock in front of a high water flow area will do mcuh the same but will take a little longer...