In addition to all of the above that applies to beginners, start writing file-listers :)
Say, write a program that lists all the files in your home directory, sorted by date, sorted by size, grouped by file-extension ... oh look, search a group of directories for movie files, of at least 1mb, sorted by date ... things like that
Snippets of code should be wrapped in
<code> tags not<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).