The second part of your proposal package is the synopsis. This is the part of the proposal I always groan to write. After all, the readers—the people I am essentially trying to reach through my storytelling—they are never going to read it. In fact, even editors don't read it with the object of being entertained. When an editor reads a synopsis, it is with the object of seeing if the contained story has an engaging and thrilling plot. Therefore, when writing a synopsis, you should be sure to list anything important.
However, beware of listing everything. Aside from the limited page count which most publishers insist on, reading it might become tedious. As the synopsis is a sample of your writing style as well as an outline of your plot, you most certainly do not want your editor to become bored while reading. Limit yourself to listing only major characters and events, turning points or any event which is necessary to explain the path to the climax. Details—like how the main character paused in her walk to admire the orange-yellow leaves on the trees—aren't necessary unless they move the plot forward somehow—for instance, if the only reason she met the hero was because she paused to look at those leaves. If it's not important, don't put it in the synopsis. Don't worry, someone will still read those brilliant scenes when they get to the actual novel.
Lastly, when writing your synopsis, be sure to keep a rhythm, same as when you're writing a novel. No two sentences in a row should start with the same word, unless you're using them for effect. Break the paragraph if it gets to be too long. Also, when listing your main characters for the first time, put their NAMES in capital letters. That way, the editor knows that they are important. (Although some editors, like those at Ellora's Cave, state that this method is outdated. Read their tips for a successful synopsis!)
On Wednesday I'll be moving on to Making Your Proposal Package Presentable!