Approaching my first Gothic cathedral took my breath away. I had never approached a structure that evoked such an unexpected and moving emotional response. A reference to a good meditation on the architecture and mystical space of a Gothic cathedral can be found here.
Even if you cannot arrange a visit right away, you can acquire Bernhard Schultz's Great Cathedrals. It is a coffee table book that covers the great European cathedrals of just about every style, but the Gothic cathedral is the central focus. Given me by a friend, it has become one of my most treasured books. There is an architectural history of each cathedral and the interior and exterior pictures are phenomenal. An online sketch of the description of a Gothic cathedral I have found beneficial may be found here. Scroll down the page and you will even find a short and helpful vocabulary list. If you can afford only one other coffee table type book (they are expensive), then add Great Monasteries of Europe. You will find there stunning pictures of a number of cloisters in the great monasteries. The picture on the right side of this paragraph is of the cloisters at Gloucester Cathedral in England, where I visited in 2006.
For a comprehensive treatment of the context and history of Gothic cathedrals, I always recommend Otto Georg Von Simson's The Gothic Cathedral. It covers everything from the aesthetic principles of Gothic architecture to the social and political history out of which it emerged. It is a great book and it can be purchased easily in paperback.
There is a great deal of excellent literature available on the design and construction of Gothic cathedrals. Excellent introductory books include The Cathedral Builders of the Middle Ages and Building the Great Cathedrals. The latter might take a little effort to find, but it is considered by many to be the book on the subject, and it will be more than worth the effort to find it.
The upcoming summer would be a great time to conduct a delightful introductory study of Gothic architecture. Then one would be prepared to plan an introductory visit to some key sites.