I have just installed an SVN server on a CentOS 5.4 machine.
Did you install mod_dav_svn (Apach httpd module) or the standalone svnserve?
how I can start the SVN server automatically at the boot of the machine.
If it is mod_dav_svn, just make sure that Apache httpd is started automatically:
sudo /sbin/chkconfig httpd on (or via System > Administration > Services if you have the UI).
I never used seriously the the standalone svnserve, but I guess you would have to start it explicitly either by: - adding the command in /etc/rc.local (called by each reboot, but may be not so clean?) - write your own script under /etc/init.d
I would definitely suggest to use it as an httpd module (much easier and flexible). It requires a little Apache config though: http://svnbook.red-bean.com/en/1.5/svn.serverconfig.httpd.html (note that this link is for SVN 1.5, but the config is the same for SVN 1.4, which is the one provided by CentOS base)