Below are the free submission links for the major search engines. A lot of engines are now requiring paid submission to their database. Some engines ignore free submissions also, so, it's a bit of a struggle sometimes to get listed in the search engines. If you don't see any results in about 3 months, then you should try and re-submit your site.
Ah-ha
http://www.ah-ha.com/list/list_addurl.asp
AltaVista
http://addurl.altavista.com/sites/addurl/newurl
Google
http://www.google.com/addurl.html
Excite - No longer taking submissions
http://www.excite.com/info/add_url_form
Northern Light
http://www.northernlight.com/docs/regurl_help.html
Lycos - No longer taking submissions
http://www.lycos.com/addasite.html
Hotbot - Temporarily unavailable
http://hotbot.lycos.com/addurl.asp
Direct Hit (influences Hotbot and MSN) - No longer taking submissions
http://www.directhit.com/util/addurl.html
AllTheWeb (including Fast, influences Lycos)
http://www.alltheweb.com/add_url.php
Free Submission To Inktomi
http://www.hotbot.lycos.co.uk/submit.html
It's a good idea to submit your site to the directories. You should only need to do it once, except for Yahoo! (try resubmitting about every three months). When submitting to a directory, ensure that you have selected the most appropriate category for your website. Directory editors are very picky about where you suggest your site.
Open Directory Project (used by Google, Netscape and many more)
http://www.dmoz.org
Yahoo!
http://www.yahoo.com/