Search Site submission is simply adding your site to search engines . like to add site on google try *www.google.com/addurl.html
except for that msn, yahoo, google & many search engines crawls others too. if you happened to add your site on google and it is linked with many other site`s yahoo, MSN & others will automatically crawl it.
In yahoo there is a option of suggest a site . But the best way to add on yahoo is to take the paid on ( It Suc** )
you can STOP the crwaling by adding a robot.txt file in the root folder of your site .
Try these free Search engine submission