Google

Google Paid Listings

Still by far the most popular search engine, Google also runs PPC ads for top "sponsored links" and side boxes via their Adwords program.

Google search free listing

If you aren't ranked well in Google for organic (free) listings as yet, this is most likely the engine you want to focus on. Google supplies secondary data to a number of other search engines/indices and sites including the mega-social networking site - MySpace.

To add your web site to Google for their free listings; use this page:

http://www.google.com/addurl.html

Yahoo Search Marketing sponsored search Previously known as Overture, it's one of the heavyweights of the pay per click industry. This model requires that you bid on keywords for ranking and at times the competition can become quite insane - some advertisers go overboard. As an example, I recently reported that on the word "computer", the no.1 advertiser had bid US$10 for the privilege. The number 2 position was held by an advertiser prepared to pay US$.77 per click. It's a huge difference.

Coupled with the fact that not everyone who clicks on the link will purchase, it can become an extraordinarily expensive marketing exercise. The COA (Cost of Acquisition) tied in with each sale may not viable for the some small online businesses, unless you are selling high profit items. The minimum bid starts at 10 cents per click.

This doesn't mean to say PPC is not a viable option - many merchants use it very successfully. If you're new to PPC, you'll want some practice and Yahoo offers new account holders some freebies - sign up and get a $25 credit.
Yahoo paid listing (directory):

US$299.00 non-refundable, recurring annual fee for commercial site in their directory. Adult sites will be charged US$600. Community, non-profit sites can still get a free listing.

http://docs.yahoo.com/info/suggest/

Note: Yahoo has two separate aspects to their search, the Directory and Web Search. Sites included in their web directories will also show up in Yahoo Web Search.
Yahoo search free listingTo submit your site for free (but you'll need a Yahoo email account):

http://submit.search.yahoo.com/free/request

MSN free listing:Up until early November 2004, MSN results were powered by Inktomi - which is owned by Yahoo. As you can imagine, this would have made Microsoft rather uncomfortable, so they are now using their own home-grown search technology.

Free submission form:

http://search.msn.com/docs/submit.aspx

MSN paid listings Another option for listing on MSN Search is as a "sponsored listing" (Pay Per Click) via MSN AdCenter. It will cost you $5 to sign up and bidding starts at 5c per click.AltaVista:Up until early April 2004, Alta Vista, which was acquired by Yahoo!, operated as a separate entity in terms of search results.

The era has ended, and now to be listed in Alta Vista, you only need to submit to Yahoo!; either through their free URL submission service or via Yahoo Search Marketing. Yahoo Search Marketing are currently offering a $25 credit.
DMOZ:Still a strong community of independent editors, free listings, but you are only listed once in most cases and having your listing updated can take a long time. Considering that DMOZ supplies data to hundreds of search engines/indices and sites, including Google, it's absolutely essential to be listed here.

I cannot stress this enough - be sure to read the submission guidelines. DMOZ editors are constantly hammered with garbage submissions.http://www.dmoz.org AllTheWeb (FAST):As with Alta Vista; now using Yahoo! results. In order to be listed, you can choose from Yahoo!'s free URL submission service or the premium service via Yahoo Search Marketing.

There are many other paid and free listing search engines around, but you're really best off concentrating on the big 3 - Google, Yahoo and MSN search respectively and DMOZ for a directory listing.