When optimising for google how important is having the keywords you're optimising for in the domain name? Although the site is only new, the site I'm talking about is still only quite a way off pg1- help!?
It can help, but it's not the be all and end all. If your site is new, don't despair at not being on page 1. You need to give it TIME.
In non competative niches it is useful. In more competative niches it is less useful. One main benefit is that when people link to you, the keyword will be in the link.
You can use keywords in URLs (site.com/my-keywords/), so it doesn't necessarily have to be in the domain. Also use your page title tags effectively.
Having your keywords in your domain name is just one of many things that can help you to improve your rankings in the serp. You should definitely put your keywords in your domain name.
If you have your keyword in your domain name its good but it make just a little difference the main thing is your tittle and quality of your content check out wikipedia its on page 1 on many keywords just because of its quality so domain name matters in beginning but in long run any thing matter is your keyword friendly titles and quality and originality of your content and more over your back links.