Ironman cycling cadence and wattage

The best thing to do is to find your lactate threshold heart rate and the wattage that corresponds with it. You can set up your training zones as a percentage of that number. There are a few protocols you can use to conduct an LT test, but I can't recommend any as I use a different method (blood lactate tests). Good luck. The CT is the best investment I've made for training.

If you have access to POWER information via the CT, you will want to find your FTP (functional threshold power) and base your training levels around that.  Your FTP number on the CT won't be the same as on your bike outside, but during winter it is good enough for now.  Are you planning on getting a powermeter for your bike?   Good document for training with power:

http://www.ultrafit.com/library/Bike/trainwithpower.pdf

A cadence around 90 is generally a good range for most riders.

Wattage targets are based upon your personal threshold.  And for a given training ride depend ion what you are working on.  I suggest you get the book Training and Racing with a Power Meter.  This will help you to better understand how to train with power. 

One of the things you will want to do is establish your FT (Functional Threshold--think of it as analogous to LTHR) which is the power you can hold for a 60min TT.  There are a variety of ways to estimate it without doing a full 60' TT.  The same 30' TT many use for HR would probably work OK.  And Andrew Coggan (a co-author of the above book) gives this list.  Then you can design training sessions based upon this FT.