There is an excellent search engine resource.
Spider Food -
http://spider-food.net/ With submission software it's not necessarily important that you're listed on 10,000 engines. Less than 10 engines cover almost the whole market.
Yahoo!, Google, MSN Search, AltaVista, AOL Search, Lycos, Hotbot, etc
I personally optimise my sites for AltaVista and Google but pay for inclusion in Inktomi's listings for MSN and AOL. At $39 for one URL it's a small price to pay.
Yahoo! is still king but losing ground to Google all the time. Recent changes in Yahoo! results has also meant Google's are more important.
I'd also get listed in the Open Directory Project,
http://www.dmoz.org - A listing here can spread your presence around the Internet more than other single action.
Google is not that bothered about meta tags, it's link popularity as Deb suggested. It's how many sites link to yours.
Google ranks all sites out of 10 using its PageRank system. If you install the Google shortcut bar on IE it will tell you the score any page receives. If a site ranked 10/10 links to your site, it's more valuable than a site ranked 6/10.
To build link popularity I'd avoid the link farms and other underhand ways as you risk being blacklisted by Google. Just go to Google and type in your keywords, work through the list of results and write to the webmasters asking for a link. It's boring work but it works. You can also set up a 'link to us' page and encourage people to add you to their home pages and sites.
You can check your site's popularity using
http://info.alexa.com which will also tell you how many inbound links you have.
You can check your link popularity on Google and AltaVista by typing 'link:www.catcherman.com'. AltaVista lists 4, Google lists 0.
According to this we have 248 links on Google to Team Nicole and 184 on AltaVista. I may have asked for 200 and got 30 or so of them added to sites but the rest came from being established a while and promotion. Useful posts on appropriate newsgroups with links to your site is another good way of building your presence. Don't say "come to my site" but say things like "I've got the answer to this on my site" and post the link. I've posted on other UBBs advertising my site using similar techniques, as long as your providing information you'll usually get away with it.
Hope this helps.