There are several ways how to enable accented characters, you can try all of them an choose the one you like most. Example document is using one I think is best (but you have to install cs
fonts (based on Computer Modern)).
You can use normal CM fonts with added diacritics (looks weird):
\usepackage{ae,aecompl}
These should look for other fonts and use cm-super
if available:
\usepackage[T1]{fontenc}
This one explicitly uses T1 with Latin Modern fonts:
\usepackage[T1]{fontenc}
\usepackage{lmodern}
And this one uses cs
fonts, looks very good:
\usepackage[IL2]{fontenc}
\documentclass[a4paper,titlepage]{article}
% encoding and hyphenation
\usepackage[utf8]{inputenc}
\usepackage[slovak]{babel}
% good looking latin2 fonts
\usepackage[IL2]{fontenc}
\title{\LaTeX document title}
\author{First Author \and Second Author}
\begin{document}
\maketitle
% write document here :)
\end{document}