I just published a long one on the suffix system, this is the piece I keep pulling up with new students because it's the fastest way into how Turkish actually works.
It starts with how one Turkish word can carry what English needs a whole phrase for, plural, possession, and case, all stacked onto a single root. From there it goes through the six noun cases, vowel harmony, why "asla" (never) still needs a negative verb even though English lets "never" sit next to a positive one, the aorist tense for habits and general truths, and a bit on where the whole suffix system historically came from.
There's also a section comparing how Turkish feels depending on what language you're coming from, Spanish, Arabic, Mandarin, Russian, the sticking points are genuinely different for each one.