When entering normal text, you must watch out for a few things. Some characters are reserved for commands to LaTeX, and are treated as such unless you tell LaTeX to treat them as normal characters. To use the characters
# $ % & _ { }
outside of a verbatim environment (see section 
for more information on environments), you must precede them with a
backslash (\), like this:
\# \$ \% \& \_ \{ \}
These characters are also reserved:
~ ^ \ < >Often, if you think you want one of these characters, you probably want to do something else.
~ can be produced in several ways. If you want a tilde
over a character, like ñ, you can type \~{n} or if
you want a mathematical you can type $\sim$ (which
stands for similar to). More often you will want the
within another math expression anyhow; for more detail
seesection below.
^ can likewise mean circumflex, as in ô which is
produced with \^{o}. In math mode you would use
\hat{o} to indicate a unit vector.
\ is not used very often in normal writing, but you can
type $\backslash$ if you want to use it.
< and > can be written as $<$ and
$>$. If you insert these symbols in your document
without quoting them as described here, they will appear as
upside-down exclamation points (<) and question marks (>).