If I consider doing one of my blog's SEO for the first time, what are the first things I have to do?

[D Dixon]

Hi Susan,
What I suggest is that you learn some of the basics before you launch into PPC. It can get expensive and I don't recommend that as a starting point because you don't know if it will yield better results for your blog or sites. I suggest you check out sites like SearchEngineJournal.com (specifically Jennifer Horowitz). Get your hands on some white papers and reports like those on blog.hubspot.com.
You need to know more about the white hat and black hat techniques out there so that you can avoid the black hat ones. Keyword research is important and figuring out the best way to do that so that you get good results.
Social media is now a part of the SEO equation so understanding how those two feed off each other is good.
So to answer your question, do your research because what worked for other sites may not necessarily fit with what you're doing and you need to be able to make your adjustments
Good luck!