A simple and effective way to gain a heart to reach the lost is to make a list of all of the people you come in contact with regularly that need to hear the gospel. Whether it's your friends at school, family members, or the person who bags your groceries, write down the names of those people and pray for them on a daily basis. God will give you a heart to see them come to Christ and will begin to soften their hearts towards the gospel.
Below are some videos and resources that are extremely helpful in sharing the gospel. Whether you are someone who shares their faith all the time, or someone who has never done it before, these videos will help you tremendously.
The God Test
The S.A.L.T. Principle
There are training videos that help you to be able to clearly and concisely answer all of the questions presented in the God Test at http://www.thegodtest.org/#!videos/cngp
Let's go reach the lost!