google, yahoo, aol, and the other engines all have forms you can use to submit your site to them.
You should also submit to dmoz - the open directory project - as many search engines use them as source info - but they do manual checks and it can take months/years before they get around to you.
If you have a link to your homepage on a related site that google regularly visits, their bot will follow the link to you and index you as well.
Google will usually to a surface scan of your site within a few days/weeks of submission. They'll to a deep crawl within a few months.