Our clients asked us - Should we do any SEO work in the first year? Should we wait?

In the beginning Google doesn't trust your website. In this case your website is not going to rank on those lucrative first-page google search results. So, the first principle of SEO is trust. When Google will trust your website your website rank will be highly. 

Trust components:

#1. Age. Indexed age (from date when Google tried to index your website).

#2. Authority profile (Who has links to your website and how quality links they are).

#3. Content. Content should be original and useful for people.

And the work to increase your website rank is really big. You need to do a lot of work to see your website in top-10 by relevant keywords. First year you may spend to create real  Authority profile with extremely interesting context. 

And if you will do nothing - you will never find your website in top-10 Google search results.