SEO modules

[atir]

Hi all!!!
Helpppppp!

I made a website (in fact still working on it) but I want to optimize it as good for search engines. Can anyone help me?
For me is very important to optimize it better, so I would have any useful tips, …what modules can be better seo
Thank you!!!

http://www.webrs.it

[atir]

I wrote this code in htaccess

RewriteEngine on
RewriteCond% (HTTP_HOST) ^ webrs.it
RewriteRule ^(.*)$ http://www.webrs.it / $ 1 [R = 301, L]
RewriteEngine on
RewriteCond% (HTTP_HOST) ^ www.webrs.it $ [NC]
RewriteRule ^(.*)$ http://webrs.it/ $ 1 [R = 301, L]

but still did not understand one thing to put the same keywords for all pages,or different keywords???
I ask because I saw different opinions!!!