I have NOT done Climb to Kaiser, save by way of helping support the ride, and over the last few years, photograph it, but regardless I have become familiar with what sort of training would be necessary to successfully complete what remains the premier distance ride of the Central Valley. To have a chance of completing C2K, one should have completed at least one hilly hundred mile ride, in six hours or less. By that I would mean a century ride with at least 7500 feet of climbing.
The first two C2K climbs can be sampled via the classic "balloon on a string" ride, Shaw and Academy out Watts Valley Road to tackle Wildcat:
http://www.flickr.com/photos/72085627@N00/755133527/in/set-72157600717992262/
http://www.flickr.com/photos/72085627@N00/749330078/in/set-72157600717992262/
then up Burrough Valley Road, down to Humphry Station, with a return via Snowman, which I recall as being around sixty miles. If you can do that ride in four or so hours, then you're in a position to consider training to at least tackle this year's Tollhouse Century, which adds to those two climbs an even harder one, Old Tollhouse.
http://www.flickr.com/photos/72085627@N00/773821339/in/set-72157600717992262/
http://www.flickr.com/photos/72085627@N00/749330062/in/set-72157600717992262/
Beyond that, at least in years past, the club sponsoring C2K, Fresno Cycling Club, would schedule specific training rides, some of which sample the upper climbs, including the real crux of the venture, the Big Creek Climb (which is actually Huntington Lake Road), followed by the dash to the pass itself:
http://www.flickr.com/photos/72085627@N00/774821382/in/set-72157600717992262/
http://www.flickr.com/photos/72085627@N00/767110014/in/set-72157600717992262/
Anyway, there are MANY CVCCA members who have actually done C2K, who can advise you whether it would be realistic for you to consider trying the ride this year, or whether a carefully planned series of increasingly more difficult century and double metric rides, culminating in C2K 2009, might be more realistic.