How are the Saints guide for Prayer?

The saints are our models for prayer by the example of their lives, their writings, and their intense prayer life.Even now in heaven, they contemplate God, praise him and constantly care for those whom they have left on earth. We can and should ask them to intercede for us and for the whole world.Their intercession is their most exalted service to God 's plan. In the communion of saints, throughout the history of the Church, there have developed different types of spiritualities that teach us how to live and to practice the way of prayer.[See CCC 2683-2684]

It is said in the Bible, do not worship or bow before any idols or images,then isn't taking a bow or kissing images going against the Word of God?

As for venerating, not worshipping, of idols and images, the coming of Christ made all the difference in how we worship God. When you read in the Old Testament, the promised people weren't supposed to worship idols because it inspired in them false ideas of what God looked like. For example, they worshipped Baal, an image of a bull and considered it as the god of fertility. The second council of Nicaea defined this matter by stating "Images aren't adored (worshipped in the strict sense), but they are honored, with the honor passing to the One represented. The same is true of images of the Saints, with the lesser honor due to them." This is like the love we express for our near and dear ones when we place photographs