how do i get my domains known on search engines without paying?

[sandra]

Lots of work. You can submit the URLs manually, post backlinks to your websites on other sites, write articles based around keywords you wish to rank for. etc

The list of things you can do is endless, how well you rank in the search engines will depend on a number of factors such as keyword competition, website content etc.

http://www.blackhatworld.com/ gives some good advice on SEO (both legit and some underhand tactics) I would stick to legitimate methods though if you want your web sites to rank well and not be penalised.