When editing a page, the Layout drop down menu offers multiple options - single or double columns. The pages on this site are nearly all structured with 2 column (simple), although this particular page just has one column to be able to demonstrate the other layout options. Two columns tend to make the text easier to read. Lines of text in single columns can be too long and cause readers to lose their place. Newspapers use columns for exactly the same reason. You can always change from one to two columns or back from the Layout menu but be aware that the positioning of some inserted objects on the page may well change and you will have to reposition them.The options with sidebars or top and bottom bars allow you alternative ways of laying out the page. One way to use a sidebar may be to add a custom navigation or items that you want to be consistent from page to page. Make the first page with the fixed elements that you want and then save it as a template to apply to the rest of the pages that you create.
To control the layout of elements on the page with more precision, use tables. Note that this can be a little tricky to get right!
In a simple layout, I may want to have 3 columns. I select the Table menu, then Insert Table and then choose how many rows and columns I need. Here I've chosen 1 row of 3 columns.
Now I am going to insert some text and images into the cells ...
Picture courtesy of Dru.
Used under a Creative Commons license. http://www.flickr.com/photos/druclimb/
When you create a page you can use text boxes to help with the layout
A text box can be alligned to the left, the right or the centre.
Add Text boxes from the Insert menu then select Properties and add your text.
It can be a bit clumsy though and shouldn't be used for the majority of layout.