Crypts are pretty hardy. I plant mine, ignore them utterly and they are obliging enough to grow anyway. Some have grown just on fish poo and good luck for six months now.
Plant it in the substrate. Feed it if you can be bothered and/or want it to grow quickly. The end, pretty much.
Thing is, depending on how different the conditions are in your tank to where it came from, your new plant might do the infamous 'crypt melt' and look dead as a doornail in about a week. If so - it won't be. Wait another week or two and new leaves will pop up, as crypts don't like change and will sulk until they've adapted to the new water.
They won't complain about a little root tab once in a while, or a bit of Flourish. I don't mind if mine grow slowly, however, in the small tanks and so those ones don't get ferts at all and as I said they are doing well anyway.
Last edited by Aus; 08-14-2012 at 02:32 PM.