Formatting Information

Use the multicol package: the environment is called multicols (note the plural form) and it takes the number of columns as a second argument in curly braces:

\usepackage{multicol}
...
\begin{multicols}{3}
...
\end{multicols}

LATEX has built-in support for two-column typesetting via the twocolumn option in the standard Document Class Declarations, but it is relatively inflexible in that you cannot change from full-width to double-column and back again on the same page, and the final page does not balance the column heights. However, it does feature special figure* and table* environments which typeset full-width figures and tables across a double-column setting.

The more extensive solution is the multicol package, which will set up to 10 columns, and allows the number of columns to be changed or reset to one in mid-page, so that full-width graphics can still be used. It also balances the height of the final page so that all columns are the same height — if possible: it’s not always achievable — and you can control the width of the gutter by setting the \columnsep length to a new dimension. There is a multicols* environment which does not try to balance the columns.

Multi-column work needs some skill in typographic layout, though: the narrowness of the columns makes typesetting less likely to fit smoothly because it’s hard to hyphenate and justify well when there is little space to manœuvre in.