Bodyweight exercises

Pushups

Weighttraining.guide push-up
Jeremy Ethier on push-ups
Proper military push-ups
Simeon Panda on push-up variations
10 mistakes
Renaissance Periodization on 11 push-up mistakes (a bit long)

Dips

Weighttraining.guide Triceps dip
T-Nation guide to the Dip
The perfect Dip (I wouldn't go as deep)
Jeff Nippard - how to do Dips (I don't really agree with going to failure, given the risks for the shoulders)
Omar Isuf and Alberto Nunez on shoulder position

Pull-up

Weighttraining.guide pull-up
0 to 5 pull-ups
5 pull-up mistakes
pull-up mistakes
pull-ups too easy ? Many variations

Chin-up

Chin-ups

Inverted Row

Weighttraining.guide inverted row
Barbend inverted row guide
Buff dudes Inverted row (short)
Chrissy Inverted row
Barbend Inverted row
Too easy ? Try pull-up rows

Air Squat

Weighttraining.guide on air squats
Form First on air squats
Squat University on squats
Squat University on your anatomy (this can influence what is the best foot position for you)
Jeremy Ethier on Squat issues / butt wink (don't worry about the breathing pattern for now)
Squat like a baby

Abdominal crunch

Tristyn Lee ab crunch

Ab Rollouts

T-Nation on ab rollouts
Ab Roll-out technique - Bryce Calvin on ab rollouts, a bit different form

Hanging Leg Raise

Tristyn Lee hanging leg raise
 

Reading material

Convict Conditioning by Paul Wade

This book describes progressions for all important bodyweight exercises (from easy to very gnarly), and gives an interesting glimpse into prison life.