Read the Book
“My sheep know my voice…”
One of the best environments in which to learn to discern the voice of the Shepherd is in the reading of Scripture. If you have not yet read the whole Book, yesterday would be a good day to start. If you really are going to read it all the way through, it might be wise to get a guide for doing it in a certain period of time. Hundreds of charts are available through various ministries for reading the whole Bible in a year, or the New Testament in a year. Finding a guide with comments might be nice, but that would be an exercise in learning the voice of the commentator, rather than the Author.
By whatever method, you should read the Book a few times in your life. Every time you read it, it will be a new Book, because it is alive and active (Hebrews 4:12).