Since our winters go kind of long, and one of my first goals is (my own) race series which takes place with snow on the ground, I try to do some intense training indoors. Okay, I also go to CA for a couple weeks, but that's different.
For the most part I can't motivate to go hard, not on my own, so it's hard for me to go hard on the trainer. I usually do steady state stuff.
I did a few winters on a VeloDyne, sort of like a computrainer. It really helps motivate, chasing virtual riders and such. A networkable trainer would be nice (Tacx) so you have live opponents. Computrainer lets you do that too.
Two caveats:
1. If you're new to the sport, I'd get rollers too, and swap between them. Trainers tend to teach very poor pedaling style. Rollers teaches good pedaling technique. I find rollers with resistance to be unrealistic (no inertia, either too hard or too easy).
2. Try a cheap trainer first. Some folks can't deal with trainer riding.
btw I have all the CTS videos and they're so hard that I've never gotten through one. I told this to the friend who got them for me (he went to a boatload of CTS camps), and he said that even the good riders won't make it initially. They're that hard. Of course, if you dial down the efforts then it's not so hard, but if you go by the numbers, wowsers. It would be good to have a powermeter or heartrate monitor for those things.
cdr