The two best astrology books I've read about marriage compatibility were Synastry: Understanding Human Relations Through Astrology by Ronald Davidson and Cosmic Marriage by Reinhold Ebertin. When I was engaged to my husband after knowing him for only six months, I needed reassurance that I was not being a 'fool in love' and I poured over these books for hours.
These books go into detail on all the compatibility aspects between two charts in their relation to a lasting love relationship. They specifically discuss all the significant aspects for love and marriage. They are not books for beginners, but I'd recommend them to anyone who already has a basic understanding of their astrology charts.
The above poster is "Marriage of Figaro" by Rafal Olbinski