Don't fall for the companies advertising they will submit your site to Google or any other search engine. If your website is new, then you can submit your website for free or just wait and the search engines will come looking for you.
The search engines love a constantly changing website. Some of the largest blogs are crawled constantly to keep updating the latest news. The more you update your website the more the bots return for a crawl and add those pages and changes to the search engines.
Be sure to use site maps for the bots. Within the site map you can tell them how often to return to your website and even how often to return to a certain page. This can be very helpful if you do not update as often as you would like. The bots do use up bandwidth and that will keep them from just randomly showing up and using more resources then they should.
Search engines are your friend but don't let people try and think that you need to pay for them to submit your websites to the search engines. This is a big scam and we get tons of emails all day long about this and even letters in the mail that look like a bill for their services. Either use a plugin for your CMS that will automatically submit your site or just sit back and wait for the bots to find you.