Hopefully these are ADULT children. Gifting property to minors is problematic. Think carefully before you do this. The minor is not able to convey property on their own (and neither can their parents). You'll end up creating a liability in taxes and other issues that they can't dispose of without legal intervention.
Unless you are selling the property for FMV, the transfer is a gift at the FMV. If the value is over $13,000 you will have to file a gift tax return. You won't owe any tax unless the value of this (and any other prior gifts you have made) is in the millions. As pointed out, they will get your low basis (what you paid for it) rather than the value at transfer. This will determine their capital gain when they sell it.
Note that you should only consider this if you have sufficient other resources that you will not need this property for anything else. You can screw your medicaid eligibility if you dump assets in certain circumstances.
