Theres no "Easy" way.
theres a million people who will say there is, and make you pay for it, but there isn't.
Bassically theres only a few search engines worth bothering to get into, and they don't accept paid submissions. (actually one making up about 5% does, I forget its name tho!!! And yahoo only accepts paid submissions to their directory, and don't even gurantee it for the $300 us)
If you visit the major search engines you can submit your site manually, it may take 4-8 weeks to get in tho by the time the SE spiders your site.
I'd goto www.google.com and www.altavista.com
yahoo/msn feed use google for their search results
Yahoo has a directory, but as I said, costs money to get in.
can try dmoz.org for the open source directory.. takes AGES to get in, assuming you do.
The most important poinT!
this is not the question to ask here, this is a oscommerce forum :)
goto www.sitepointforums.com and check out their forum dedicated to search engines. Read the top sticky posts in each section, then re-read them, then think about submissions :)