One thing it has, in the back, is a section on building an opening repertoire. In that section are two tables which I will take the liberty of reproducing here. If you like this - go buy the book. It covers what you need to know about the openings - HOW to conduct them, not just memorizing a crapload of variations.
So, first table: Openings with structural similarities.
Openings and defences | Factors in common |
Slav, Caro-Kann, Scandinavian, Torre, London | Pawn Structure, queen's bishop outside the chain |
Dutch Stonewall, French, Open Spanish | Pawn structure, opposing pawns in the center |
Benoni, Pirc, Closed Spanish | Pawn structure, dark square play |
Nimzo-Indian, Queen's Indian, Bogo-Indian, Sicilian Scheveningen, Taimanov, and Kan | Pawn structure, queenside fianchetto |
King's Indian, Pirc, Modern, Sicilian Dragon | Pawn structure, kingside fianchetto |
Queen's Gambit Accepted, Petroff | Pawn structure, open game |
Grunfeld, Catalan (some lines) | Pawn structure, kingside fianchetto |
Sicilian Dragon Accelerated, English w/ g3, Symmetrical English (as Black) | Pawn structure, kingside fianchetto |
Sicilian Rossolimo, English w/ 1...e5 and ...Bb4 | Pawn structure |
Colle, Semi-Slav | Pawn structure |
King's Indian Attack, King's Indian, Pirc, Old Indian | Pawn structure |
Tarrasch, Petroff, Sicilian Alapin, Queen's Gambit Accepted, Caro-Kann Panov Attack | Pawn structure |
Okay, that groups the openings together by their typical pawn structures. Now, openings with similar "styles."
Openings and defences | Factors in common |
Queen's Gambit Accepted, Petroff, Spanish Berlin, Sicilian Alapin, Spanish Exchange, French Tarrasch | Solidity, piece exchanges, endgame perspective |
King's Indian, Sicilian Dragon, Dutch Leningrad, French 3 Nc3, Open Sicilian | Aggressiveness, closed or semi-open positions |
Semi-slav, Spanish Marshall, Archangel, and Schliemann, Car-Kann w/ 3f3, Open Sicilian | Aggressiveness, open or semi-open positions |
French, King's Indian, Czech Benoni | Closed positions, pawn chain battle |
Queen's Gambit Declined, French | Solidity, closed positions |
Dutch Stonewall, Sicilian Sveshnikov | Weak points, activity |
Sicilian Najdorf, Grunfeld, Sicilian Dragon, Semi-Slav Botvinnik | Theoretical battle, sharp play |
Nimzo-Indian, French Winawer, Sicilian Rossolimo, English w/ 1...e5 and ...Bb4 | Surrender of the king's bishop, doubled enemy pawns |
Catalan, Benko Gambit, other gambits | Pawn sacrifices, activity |
Sicilian Scheveningen, Kan and Taimanov, Alekhine, Pirc, English Hedgehog | Space disadvantage, flexibility, few piece exchanges |
Trompowsky, Chigorin | Surrender of the queen's bishop, imbalanced play |
King's Indian Samisch, Classical Nimzo-Indian | Space advantage, slow |
So, if you're looking for a new opening, choosing something within the same group might prove easier to learn and play effectively.