New here and Need Help in “Natural SEO”!

[hategate]

I own and operate two sites for fun. If possible I may be able to get a business' to place ad's on my site. Like I said these sites are for fun not profit. I want to get more members though. How do I get my sites to pull in more members with search engines. Are there any tricks you could show an average person to make their site more visible. I have been able to figure out quite a bit from hands on experience as far as operating the sites goes. I thought it might be more than I could handle but sar far so good. Thanks ahead of time for any help you may be able to give.
Thanks again

[freshfroot]

The tips and tricks are ALL done with NuSEO. It's settings and system will do all the proper SEOing needed for search engines.