The only way to make your website searchable is submitting to the search engine.
There is a lot of search engine nowaday. But this is the fact, submitting your website too google and yahoo would be enought.
If your website indexed by google and yahoo than it will be automaticaly indexed by many other search engine such as MSN, alltheweb, AOL etc.
Here is the url for submit your website to google
http://www.google.com/addurl/?continue=/addurl
And this is the url for submiting to yahoo