Search Engine Site Submission
Submitting your site to a few major search engines (google, yahoo, msn bing, ask.com)  From there a lot of the smaller search engines will see and reciprocate, as they are constantly trying to battle the big dogs.
http://www.google.com/addurl/
http://siteexplorer.search.yahoo.com/submit
http://www.bing.com/docs/submit.aspx
http://about.ask.com/en/docs/about/webmasters.shtml#18  

Meta tags : Keywords    
    Keywords: Keywords should encompass what you talk about on your site.  In other words if you have a site based on green energy, health products it would harmful to your search engine results to have a keyword of puppies.  Keywords should be representative of what you write on your site, and vise versa.  If you talk about solar power, in the body of your pages, then it's beneficial to use solar & power as keywords.
Amount of keywords:  "Less is more"  You should limit the amount of keywords you use on your site to between 20-30 words.  Less then 20 and you won't cover what you do, more then 30 and the search engines start to ignore you.  Some of the "not so great" sites back when search engines really started catching would toss 500+ keywords in to try to suck up the results.  Search engines fixed that by limiting the total amount they deem acceptable.

    Keywords example: Black Hills, BlackHills, lodging, motels, campgrounds, events, Rapid City, Spearfish Sturgis Rally Events Schedules, Gold Jewelry.......

Don't run the words together though unless its intentional (blackhills, separating out "black, hills" is beneficial, capitalization is also irrelevant) Above all else do not repeat yourself, (i.e. Wrong way (6 words) = "black hills, orange hills, green hills"  Right way (4 words) = "black, orange, green, hills") repeating words only adds to your total count, leaving yourself room to add more words that help define your site will only benefit you.

 

Meta tags : Description    
    Description: The description is the small blurb you see on say Google under the link.  If you don't have this they usually take a chunk of what you're saying from the body of your page.  But it's useful to make a description that follows your keywords.
    Description size: It is recommended to keep your description between 250 - 300 characters (including spaces), again same as with keywords less and or more can hurt you in the same way.  Reasoning is the same as for keywords on why.  But so long as you're description matches what you do in less words less then the 250 will do well for you too.

    Description example:  BlackHills.com - information about the Black Hills area. Lodging, Motels, Campgrounds, restaurants, Businesses, Events Schedules, Weather, News, Pictures, Business Members Website Links and more!

 Couple other important "tags"

Title:
    The title of the site is important for search engine results, not as important as keywords, but close to if not the same importance as Description.  A good example for the title of a site would be...  BlackHills.com - Lodging, motels, campgrounds, restaurants and other Black Hills Information.

 

Image "alt" tags (alternate text):
    Search engines do not see images the same way we do.  The see <img src="path/to/file.jpg" width="10" height="10" border="0">.  The trick to help a search engine catalog / index an image call, is the alt tag.  <img src="path/to/file.jpg" width="10" height="10" border="0" alt="preferably unique info about the picture itself">  This trick is also useful in image map images (<img src="images/home-big.jpg" width="979" height="312" border="0" usemap="#Map2" alt="Home - Products - Service - Contacts - About us">)  It all seems a bit redundant but this does help in search engine results.

 

Text based links or Sitemap : 
This seems redundant for websites but a set of basic text links at the bottom of a site or sitemap can make it easier for a search engine to index your many pages.  To clean up the process a Sitemap page could be made with a text link at the bottom of your pages (simply add a sitemap link to terms of use | privacy policy | purchase policy currently at the bottom of your site).  Then in the resulting linked page for sitemap, define each of your sites pages with a simple text link in the body of the page.

XML (or similar) Sitemap:
    Same as above BUT in .xml format, this one can be hard to get started, you "link" to it similar to a css(cascading style sheet) but holds information regarding the pages in your site.  There are other options you can use this for as well.  The biggest one is with google.  You need to create an account with google.  Then submit the xml file to them.  This can be useful for more then just google, as the little guys scramble to pick you up same as google. 
http://www.sitemaps.org/

Traded Links:
    Traded links, or reciprocal links can help a search engine categorize & catalog what you do.  Trading a link however to a site regarding puppies when you're running an alternative energy, or health care site won't help.  Try to keep to trading links with like sites, science news, webmd, etc, etc.  Similar to the sitemap above, a simple text link to a traded links page is more then enough.