This how - to is primarily for  both  Editors and Managers (site designers already know this)

Why Read This:   you may have to look at what the editor generates and it will help you find what you are looking for.

Background:  Web pages are not printed documents.  They are designed to be viewed on screens of various sizes.  The page you prepare using a word processor is designed for a certain printer and to go on a piece of paper usually 8 ½ by 11 inches in size with a certain size margins.   The language which the browser understand is HTML (Hypertext Markup Language).  The Editor in the CMS system is just a fancy way to generate this HTML so you don't have to know the details.    If you want to see what is generated, just click on the HTML button in the editor and you will see the raw HTML.  You will see the words you type

HTML tags:   All HTML components begin with an open angle bracket "<" and end with a slash followed by a close angle bracket "/>" .  Some components occur in pairs (for example tables begin with a TABLE tag and end with a /TABLE tag, each tag begun with the open angle bracket and ending with the close angle bracket.  Some other HTML components occur signlely (e.g., the HTML for a horizontal line, that is: <br />

Here are some common tags (I've removed the angle brackets because so the web browser doesn't hide them as HTML commands).

P and /P begin and end paragraphs
Strong and /Strong begin text which is bolded (note B and /B can also be used for this).

OL and /OL begin and end ordered/numeric lists while UL and /UL begin and end unordered/bullet lists.
Each entry or list element begin and end with LI and /LI

TABLE and /TABLE begin and end tables 
tables are built one row at a time (TR and /TR are the elements which begin and end a table row).
TD and /TD begin and end the individual table data element (sometimes called "cells").    You can joint table data elements either horizontally or vertically using the editor by highlighting the desired cells and clicking on the Join Cells icon in the editor.  Tiy can specify how text will flow around an image.  This flow may extend to other cells within the same row.  If you are familiar with a spread  allow you to add rows and/or columns, combine and/or split them.

Limited fine tuning of appearance is possible by use of "Styles" which can be applied to any HTML component.   If you are interested please look up CSS in GOOGLE for more information.  Your web site may have a number of built in styles which you can access via the Styles drop down.