Son breaking computer given books, lucky thing (6)
I believe the answer is:
mascot
'lucky thing' is the definition.
(I've seen this before)
'son breaking computer given books' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'breaking' indicates putting letters inside.
'computer' becomes 'Mac' (Apple Mac computer).
'given' is a charade indicator (letters next to each other).
'books' becomes 'OT' (Old Testament).
's' going inside 'mac' is 'masc'.
'masc'+'ot'='MASCOT'
(Other definitions for mascot that I've seen before include "One for good luck" , "Symbolic figure, of a team perhaps" , "Thing considered to bring good luck" , "One is lucky" , "that's charming?" .)