If you want to use symbols for footnotes, rather than increasing
numbers, redefine \thefootnote
like this:
\renewcommand{\thefootnote}{\fnsymbol{footnote}}
The \fnsymbol
command produces a predefined series of symbols
(see \alph \Alph \arabic \roman \Roman \fnsymbol). If you want to
use a different symbol as your footnote mark, you'll need to also
redefine \@fnsymbol
.