I'm an intermediate HM user, but still don't know some basic things like - not only what does certain stats mean - but what percentages are we looking for in these stats? The basic ones are Aggression, went to showdown and everything about showdown, and 4bet ranges. I'm actually more a PLO player but posted in the NLHE because there is more activity here and this all started with HE, so I'm open to a HE article or a PLO article since I'd like to become proficient in HE once more.

i.e. Flop Aggression. Let's say it's 1.5. What does that mean in terms of telling me something about villian? What would 1 mean? 2?

I'm sure there is a nice website/article that clearly explains at least the basic foundation stats and how to use them. I'm also open to advanced stuff.

Thank you.

Aggression % is a much better stat : it tells you how often you raise/bet as opposed to check/call.
Aggression factor doesn't take in consideration the times you fold, ex: you'll have infinite agression if you never call even though you fold 9 times out of 10. Worthless stat imo.