If you are somewhat (well... very) familiar with computers and computing, you could use a music typesetting package called musicTeX (pronounced music-tech). It is a set of macros for use with TeX, Donald Knuth's typesetting system. You use a standard text editor to enter the input and the musicTeX macros together with Tex itself will produce a professional, typeset score. Here is the text input needed to typeset the first two bars of Mozart's K545 Sonata in C-major.

\begin{music}
\parindent 1cm
\def\nbinstruments{1}\relax
\def\instrumenti{Piano}%
\nbporteesi=2\relax
\generalmeter{\meterfrac{4}{4}}\relax
\debutextrait
\normal
\temps\Notes\ibu0f0\qh0\{cge}\tbu0\qh0g|\hl j\enotes
\temps\Notes\ibu0f0\qh0\{cge}\tbu0\qh0g|\ql l\sk\ql n\enotes
\barre
\Notes\ibuf0f0\qh0{dgf}|\qlp i\enotes
\notes\tbu0\qh0g|\ibbl1j3\qb1j\tbl1\qb1k\enotes
\temps\Notes\ibuf0f0\qh0{cge}\tbu0\qh0g|\hl j\enotes
\finextrait
\end{music}

It isn't pretty but it only does charts. No sound-related stuff that you'r trying to avoid and what's more, it's all available free. Your best bet for a good TeX distribution is emTeX; search for CTAN, TeX, LaTeX, and of course muTeX. It's some trouble to get up and running but the side benefit is that you'll be all set to go into the commercial publshing business.

Personally, I prefer a commercial program called Finale. It's expensive but you can play two-handed music on a MIDI keyboard and have it show up as a score.

Good luck,

- Mark