I want to know how to set things up before I do the content and backlinks etc so I don't have to come back and re do it all.
For example, I will use Yoast SEO and Google analytics etc. Should I use something like genesis framework?
Some essential plugins that I install are:
all in one SEO - sitemap
cookie notice - required by law
really simple SSL - help stop any SSL issues
word fence - essential firewall
Easy Updates Manager - update all themes plugins
Whisper - interlinking
Autoptimize - optimization
In terms of which theme you should use, there are too many out there to suggest a good one, and you won't rank top spot, just because you have a certain theme, just play around with a few, maybe write a couple of dummy articles, to see what the site looks like. You want to be happy with how the site looks, and it should look good for your visitors too. Also, remember to stick a privacy policy up, with the t&c of your affiliate program.
Test everything you can on the site, like on mobile, testing menus etc. There can sometimes be just a make or break issue that will have you sticking with a theme or not.
Make a list of any things that you want to change in the theme, like removing footer etc, and get a Wordpress programmer to do that all in one go.