Uh oh. The Bishop just asked you to give a talk next week in Sacrament Meeting. From the sound of every Sacrament Talk Ever, this is something most people avoid. You're not a public speaker. Why couldn't the Bishop have asked Brother Smith who has something to say for every question in the Gospel Doctrines class?
Relax. This doesn't have to be a big deal. Almost no one who gives a talk in Sacrament Meeting is an experienced public speaker. I took debate for three years to gain some confidence to speak at church, and I still get nervous. However, as long as you are prepared, the Spirit will fill your mouth and you will touch the hearts of everyone in the congregation.
Step One: Identify your Topic
This is usually pretty easy because the Bishop just gives it to you. If the Bishop gave you free reign, pray about it. If he gave you a talk to speak on, boil it down to one or two words. Then take some time to meditate on it.
Step Two: Research
This step should take most of your time. Spend a few hours or days just doing research on your topic.
Scriptures
Church Magazines
LDS.org for basically everything else
True to the Faith is a great resource for simplified definitions of gospel topics.
Preach My Gospel can help a lot too.
Step Three: Write an Outline
This is just like writing an essay. Remember how you thought, "I've graduated from school. I'll never have to write another essay ever again!" Well, you were sadly mistaken.
The ward loves to hear your personal experiences, so don't avoid using
them because you think you're boring. You are awesome and unique and
stuff. Your experiences helped build your testimony, so use them.
This is my favorite outline. Change up the order or add/delete stuff as needed.
Introduce yourself and your topic
Point One
-Scripture
-Quote from a talk
-Personal experience
Point Two
-Scripture
-Quote from a talk
-Personal experience
Point Three
-Scripture
-Quote from a talk
-Personal experience
Close with Testimony on topic
Step Four: Flesh it Out (optional)
Some people like to speak from an outline. I do not. I like to write out my essay/talk/oration. The more research you've done, the easier this will be. The better you understand your topic, the simpler you will be in explaining it.
Step Five: Practice on your Cat
Your cat will judge you far more than the ward will. Practicing will help you get out some of your jitters.
-or-
Step Five: Practice on an Unsuspecting Non-Member Friend
Why not do some missionary work while you're working on your talk? Practice on a trusted friend who won't be mean, but can give you some constructive criticism.
Step Six: Give a Masterful Talk in Sacrament Meeting that goes Better Than Expected
Prepare yourself for all of the compliments you will receive from the ward. It's not just an assignment; you have helped them feel spiritually uplifted.
-or-
Step Six: Ignore Your Outline or Pre-Written Talk Entirely as You Follow the Spirit When You Speak
This happens to me more than I thought it would. It's entirely possible for the Spirit to give your talk for you, but you have to have something prepared and have done some of the work.
Congratulations! That wasn't too painful, was it? As an added bonus, you've learned far more about this particular topic than you ever thought you would. Teaching is one of the best ways to learn about any gospel topic. That's probably why Heavenly Father has us give talks in Sacrament meeting.