Yes, especially the specific pages that link to yours. It'll bump you up in the rankings.
Most webmasters submit their sites about once a month. Any more than that, and you might be labelled a spammer. It keeps track of the IP of the submission, so the more unique IPs that submit a site, the better the ranking. If sites with a higher ranking link to you, your ranking goes up as well.
If you didn't know about submitting to Google, were you aware of DMOZ.org? Most search engines on the web use that as a category reference. It's essential to have your site in at least one category at DMOZ if you want people to know the site out there.
http://pub80.ezboard.com/beverythingspace">Everything Space