Submit To The Main Directories

The more high quality links you have to your site, the more impressed the
search engines will be.

Start with major directories such as...
Yahoo!
DMOZ.org
sbd.bcentral.com

...and move on to...

Gimpsy
Skaffe
Joeant
GoGuides
Business.com
SevenSeek
ThisIsOurYear
LookSmart (probably too expensive)
BlueFind
WowDirectory
Best of the Web
GeniusFind

Here's a good list of directories
http://www.strongestlinks.com/directories.php

Be sure to read the submission rules carefully at each site. This will slow
you down but it increases your chances of getting your site listed. Listings
can last for years, so it's worth while taking your time to get the details
correct.

You may want to outsource this task by finding someone at a site like
eLance or hiring a student.