Well, I just started riding a trainer in Jan 08. So I'm still a newbie.
My training schedule has been:
Monday- 1.5 hour ride
Wednesday- 1.5 hour ride- intervals
Saturday- 3 to 4.5 hour ride- outside if the weather is nice, inside if not.
The TV can keep me entertained for a long time. I just store up my shows on my DVR and watch them while riding. This makes me look forward to being on the trainer.
When it gets tough, I turn on the music. That motivates me to finish my time off.
This past Sat. I did a 4.5 hour trainer ride (my longest to date)... and for the last 1.5 hours I watched the rerun of Kona 07. Very motivating.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"