Besides from learning chord you should practice them. This is obvious, but sometimes you need a method and the following are resources for exercising guitar chords.
Shifting between chords
The first section is based on basic chords. The foundation in chord playing is two shifts between chords efficiently. The first parts of these exercises involve chord shifting on each bar, and the last part raised the level by shifting within the bar. The strumming patterns are only suggestions, the important thing here is to practice your ability to make smooth transitions between two chords.
Minor chord exercises (.pdf)
Major chord exercises (.pdf)
Chords with increased complexity
Chords that involve many fingers are normally harder to play than chords involning few fingers. Another important thing is to practice the less common chords. By vary the chords you're playing you will become more flexible. These exercises therefore goes from ordinary major and minor chords to involve some sevent and ninth chords.
Chord repertoire maintenance
There is a limit of the amount of chord we can keep in our memory. But with right methods we could at least make the best of our memeory capacity. One way to help our memory to keep track of chords is to recognize the similarities between chord and by that better organize our knowledge. As the following chord exercise shows, there are often small differences between chord shapes.
The following exercise are not so much playing practice, more as recognition hints that gives you insights how chords are build.
Chords recognition (.pdf)
Play trough chord progressions
Another ways to practice chords are playing through progressions. These chord progressions collections can be find at this site:
Learn useful chord progressions - fundamental ways to construct progressions
Advanced chord progressions
Chord progressions in various keys
Chord progressions in famous songs