In the past three days I have heard / seen reference to Butterick's Practical Typography. First there was Merlin and Dan talking about it on Back to Work #133 and then later I see MacSparky's post. There is an entire "free" online book there for your consumption. And, if you don't have time to read the entire text, give yourself ten minutes to read his Typography in Ten Minutes section. That alone is worth the "price of admission". Seriously, though, this guide includes some very practical information that deserves to be added to your Pinboard or Favorites list.
If you are like me, one who often struggles with an underlying desire to use Time New Roman or Arial, give this a quick look. I believe you will find it something worth reading.