SEO deer in the headlights

I do not understand SEO at all. I kind of understand what it does? Makes your blog easier to find in searches, yes? But all of the SEO plugins are overwhelming and I have no idea which one to use or even how to set it up?

Surely there is a God sent link that explains SEO and how to set up/manage certain plugins for it?
Please help a girl out in over her head.
Thanks so very much
Tami