To network your repository over HTTP, you basically need four components, available in two packages. You'll need Apache httpd 2.0, the mod_dav DAV module that comes with it, Subversion, and the mod_dav_svn filesystem provider module distributed with Subversion. Once you have all of those components, the process of networking your repository is as simple as:
getting httpd 2.0 up and running with the mod_dav module,
installing the mod_dav_svn plugin to mod_dav, which uses Subversion's libraries to access the repository, and
file to export (or expose) the repository.
You can accomplish the first two items either by
compiling httpd and Subversion from
source code, or by installing pre-built binary packages of
them on your system. For the most up-to-date information on
how to compile Subversion for use with the Apache HTTP Server,
as well as how to compile and configure Apache itself for
this purpose, see the
INSTALL file in
the top level of the Subversion source code tree.