Adding some cycled media will help jump start the cycling process. Adding tank water will do little as there is no such thing as 'cycled' water. Bacteria live and colonize on surfaces such as your filter media where there is ample oxygen and a constant source of food.
Do you plan on doing a fishless or fish-in cycle? Fishless, you will need to add an ammonia source such as bottled ammonia to keep your bacteria fed. Fish-in can be done safely but toxin levels need to be constantly monitored to keep them very low (below .25ppm) and lots of water changes will be a must. Stocking minimally to start then stocking very slowly once the tank is cycled will help ensure the cycling process will go smoothly.