Prepare the Script
Some people just don't believe in preparing a formal script for a presentation. If you have given the same presentation a thousand times, it is entirely possible you could give an outstanding presentation based only on your outline. For expert presenters, this strategy works well. However, if you struggle with making presentations, if you are nervous, or if it is absolutely essential that you make a great impression, then writing out the script is a great idea. More than likely, you won't follow the script word-for-word during your presentation, but knowing what you want to say will ensure that you say everything you need to.
Parts of a Presentation
Of course, there are all kinds of ways to present, but a simple formula is to include an Opening, Body, Summary, Q&A, and Closing in every speech.
The opening is where you explain "what has happened/what needs to happen." Then you can quickly state the purpose of the day's meeting. State the main concepts that your attendees absolutely must remember. Depending on the amount of time you have, your opening may take several minutes, or it can just be a few sentences long. If I were presenting my previously described argument about why my son should go to bed on time, my opening would be very short.
Example (using the bedtime argument)
Once I have that all written out, I can choose to dress the basic verbiage up and make it into real sentences, in a kind of language that is appealing and appropriate to my son (the audience). The degree of pre-planning I do depends on the amount of time I have for the actual presentation and how much I plan to use my notes. For the purposes of this exercise, I am going to assume we want to keep things simple and not get very flowery. That will make it easier to remember what needs to be said, and will avoid dependency on written notes.
The body is simply the detailed explanation of all the basic arguments we have already outlined, and the summary is another opportunity to re-state the central points we want to make sure our audience remembers. Although written and oral communication has a lot in common and they developed out of the same root, one key difference is that in writing, you do not want to beat your audience over the head with an idea. Sometimes, when you are addressing a group verbally, you have to restate the same thing over and over again to make sure that your audience takes away right key points.