Dear Sleepless in Seattle....
First of all, I'm guessing it's the transmitter that you're fighting with. They give you a plastic zip-tie sort of strap device to hold it on, and you're having trouble getting it to line up correctly with the magnet,
OR, you got it on, but it's too far from the magnet.
OR, you can't get the magnet onto your spoke.
Second of all, it takes a minimum of three hands and a pint of Guiness to accomplish this.
Since I'm in Michigan, all I can tell you to do it be patient.
also know that some of the newer carbon fibre forks are so oddly shaped that they dont accomodate the transmitter.
When all else fails, take it to your LBS (Local Bike Shop).
If you bought it on line, take it to your LBS and apologize for buying it on line and then ask them for help.