Paul's words in 1 Corinthians 9:19-23 are still fresh on my mind; can we be all things to all the people of our community in order that we might win some?  If we're going to do that, then we have to be clear about what it means to "win some" and how we are supposed to go about doing that.  One of the most helpful books that I've read on evangelism is Will Metzger's "Tell the Truth."  If you want to have a better understanding of what evangelism is all about and guidance on how you can be a more effective witness for Christ, then I recommend you read this book.  You can or it here.