re: Brother wants me to teach him how to play guitar. Where should I start?

Step one: simple chords (no bar chords)
Step two: how to read tab
Step 3: power chords and simple bar chords to start building strength and callouses.
Step 4: scales (major, minor, & pentatonic) and rudimentary theory (4 chord songs, I/V/VII, b flat blues, etc)
step 5: full bar chords
Step 6: hammers/bends/tapping
Step 7: finger picking
Step 8: bends
Step 9: advanced scales (modes like dorion and ionic) and theory