Crypts are heavy root feeders, so root tabs are a must. I don't use liquid fertilizers with mine and they are in a dirted tank, so I don't use root tabs either. Mine are probably the hardiest kind, wendtii, and they grow about 4-6 inches tall in my tank. They are happy and healthy in low lighting @ 1.5 watts per gallon, producing loads of runners.
I'm not familiar with the type you have so they may end up growing pretty tall. I've yet to have any of my crypts melt back, but I hear it is quite common so don't pull the plants if all their leaves die off, just wait a few weeks to see if they grow back.
To plant, just trim the roots to about 3-4 inches, also trim any damaged or yellowing leaves and then gently push them into the gravel. I like to hold the ends of the roots by my finger tips (like a pinching from) and then put my fingers into the gravel and let them go when they're deep enough. You can use larger rocks to keep them in place if they don't want to stay.