You've posed a very common question.  Wisteria most often will take a long time to bloom initially, sometimes a very long time, usually years.  Depends on which variety you have an how the plant was grown.  If your plant was grown from seed, it will take 10 years plus before flowering.  Much sooner if from nursery stock. Assuming the plant sits in full sun (important), 5-6 hours or more, and pruning is done at the right time, the best thing to do may be nothing.  Less sometimes is more.  Many do bloom in 5-7 years without any intervention. You can read much more below.  Suggestions are to fertilize, but only with phosphorus. No nitrogen, which encourages green growth at the expense of flowers.  The only other suggestion might be to root prune as described in one of the links below. 

Once it does begin flowering however, it should flower every year faithfully for you.  A robust grower that some consider a thug, it needs sturdy support but can be a very beautiful plant when flowering.  Wisterias drape many of the centuries old castles all over England and the look is quite stunning when flowering in spring.

Here's more:
http://www.hort.purdue.edu/ext/wisteria.html

http://ohioline.osu.edu/hyg-fact/1000/1246.html

http://web.extension.illinois.edu/dmp/palette/100425.html

Good luck!