Do I really need a robots.txt file and what else helps with SEO?

[The IT]

The most important piece of advice I can give you is to "be who you are" on the web, and not try to manufacture false views by pretending to be something else.

Google changes its algorithm every so often and the changes can be details here:
http://www.seomoz.org/google-algorithm-change

Also regardless of your industry, make sure your website has a Twitter and Facebook account associated with it - perhaps Pinterest too if you are very keen!

What makes SEO effective differs between who you talk to but the common ground is details in the article here:

http://theithandbook.com/2012/09/10/webs...h-engines/

Also it's really worth getting some analytics so you can see usage trends in terms of who views your site how many people bounce straight back to Google, what keywords they found you via etc. Google Analytics is incredible and its free, have a read about it:

http://theithandbook.com/2012/10/18/goog...-business/