I usually take notes of:
Brewing salts used additions in grams or ml and a snip of tab 5 in brunwater
how the mash went volumes starting temp, strike temp, temp log every 15 mins after mash starts, pH every 15 mins, adjustments if necessary and what those are
preboil OG, log additions at exact times, start of wp/chilling time, post boil og, and pH at time of pitching yeast
Pitchrate and strain info
Fermentation and temp log
carbonation level and priming sugar used
storage temp for carbing
then tasting sheet from craftbeer.com for each batch.