Since you asked what horoscopes looked like I thought I would throw in a few images.

The Tres Riches Heurs from the early 15th century includes zodiac signs as part of the calendar. It also includes this really famous example of the zodiac signs corresponding to parts of the body. The zodiac man convention was a very prevalent theme, they were considered a part of legitimate medical understanding as it was believed those parts of the body were influenced by the sun and moon and time of the year.

Another common style is the zodiac wheel (16th C. example). Zodiac wheels are often very simple, only depicting the symbols, or are incorporated into more complex designs, as they were both functional as calendars and as decorative pieces.

Zodiac symbols were also often used as an artistic motif of as a way of representing the heavens. The relationship between Christianity and the zodiac is complicated and probably better explained by someone else, but there is certainly a lot of Christian art that incorperates the symbols. The tympanum of St. Lazare at Atun (12 C.) has the zodiac surrounding Christ as a symbol of his domain over all things.