Installing openldap on Etch is incredibly easy. The Debian maintainers did a great job at automating the installation for you. It sounds like your openldap install has been corrupted some how.
Normally, you would just do:
# apt-get install slapd
Debian would fetch the files it needs, examine your system to determine your server and domain name, ask you what 'admin' password you want, then automatically create the /etc/ldap/slapd.conf file for you, install the /etc/init.d/slapd start-up file, create a default DIT, add the admin user, and bring up the server! Debian is great... other distro's don't do any of these things. They just install the program files, then leave you to figure out everything by yourself.
Since it sounds like your openldap is messed up somehow, I'd say do a reconfigure on it first.
# dpkg-reconfigure slapd
This will reforce it to ask you configuration questions, then regenerate everything for you, like in the original install.
If you are new to openldap, I should warn you it can be very hard to learn. Depending on what you want to use openldap for, it can be quite challenging.
As for how-to's, most are written for Sarge. I haven't seen any good ones written for Etch. Here's a good one I've used, it was written for sarge (3.1), but works for etch (mostly), and covers openldap and samba integration pretty nicely:
If the above dpkg-reconfigure didn't help, then I'd suggest totally uninstalling the slapd package:
# dpkg --purge slapd
Normally, when you uninstall a package in Debian, it removes everything EXCEPT the config files. The --purge will tell it to remove everything. That way, when you re-install, it should be from scratch.
If you still get errors after reconfiguring and uninstall/reinstalling slapd, I'd suggest if that's a new install, format that hard disk, and start over. I get the feeling you might have tried installing from source... on Debian, it is always best to install from packages when they are available.
Hope this helps