Not quite sure what you mean by " website to be hit " ? If you want to know about SEO before you build your website, get a book called Search Engine Optimization an hour a day- by Jennifer Grappone and Gradiva Couzin. Not expensive and will help you from the start.

You could optimized it later. The only thing you'd probably want to optimize in the design/creation process is the linking structure (how the pages link together). You could then go back later and add on-page SEO like title tags, description tags, etc.

Have you picked the Domain name yet? If you can use a domain that has your niche in it that would be good. As the others pointed out, structure and links are important so I would make sure you have someone who knows seo, help you with designing it.

Sure ... you need an SEO or you can SEO your website both in and out. meaning inside the website and outside means your links from articles etc...

If you mean by hit is to get your website popular. You can get a lot of help to SEO to improve the search engine ranking of your website.

Well you do want to design the site with SEO in mind and you will definitely get better long terms SEO results that way.

Simple answer:

Your best bet is to have it designed by a designer that understand SEO and have it built with SEO in mind from the ground up.

I urge you to learn about SEO first and then incorporate it into your site. It is not good to look for short cut. I did to my own detriment. Please, take the time to learn. Warrior forum is the best for you. Once you fully understand, then start putting into practice what you learn.