There's a fantastic little book called Don't Waste Your Life written by John Piper that I would like to recommend to everybody. In the end you don't want your life to be wasted. This book does a good job helping you see the right perspective on living this life so that you don't waste it.
Here's the website by the same name. On the website you can order a paper copy of the book or you can download a .pdf of the book for free, and they've got some great little video podcasts that come out about once per week.
Happy reading. If you've already read this book, what do you think???