The Wheel of Time series was originally written to contain six novels in the series. Now there are twelve published books in the series and two more novels are yet to be published. There is also a prequel novel and companion book available to go with the acclaimed fantasy series.
There are twelve published books in the Wheel of Time series by James Oliver Rigney, Jr, who's pen name is Robert Jordan. He has plans for at least 2 more.
I've read a couple of "Wheel of Time" series myself. As of July 2010 there are twelve books in the series. There is a thirteenth book due to be published later this year, and a fourteenth book in 2011.