Not a pro, but here goes.

A trainer workout is only as good as you make it. You can make it any workout you want, from a constant grind to an easy-peasy Sunday afternoon ride. The trick is knowing what you want out of your workout before you get on the bike, and then adjusting accordingly.

That said, while you could technically train by distance (using a sensor), the distance won't mean anything since wheels spinning indoors bares no relation to what's going on outside. Training by time is far easier.

What do you want out of your time on the trainer? (Same question you'd ask on the bike, ideally)

+3 for TrainerRoad. I did a cycling focus on the trainer one winter and came out with more speed and endurance than I'd gained over any other season.

I'm a little dense here, I think. I have a supported trainer, but no power meter. They say it still works with an ANT+ or Bluetooth Smart speed sensor. Can someone give me an example of one of these? Like a Garmin cadence sensor? And then it talks to your computer through Bluetooth?

Indoor ST pros -

As part of my training I do swim/cycle bricks on Tuesday and Thursday evenings. The route is always the same with varying efforts based on RPE, weather, etc. The ride is 40km on the dot, however due to traffic and other conditions outside of my control, my moving time is anywhere between 1:10:00 to 1:45:00.

I have never used a trainer before, and I just got one (a basic one). I don't want to get a less quality ride than I do during the week already. Can you train on a trainer by 'distance'?

Should I train by time?
Should I train by RPE or HR?

I will still be doing my long rides on the weekends on the road.

I don't have a power meter.

I ran into the same conundrum, actually you need to purchase a little USB stick that can receive ANT+. Garmin, Suunto, and I think a few others make these. They are rather cheap, $20-30 I think. Without this you can't really use TR, though you might be able to do the HR based workouts.

After you get the stick, should be able to connect your ANT+ sensors to your computer and TR should recognize them.

However this is all theory and with basically everything in my life I really have no clue at all.

Since I am waiting for the arrival of this piece of gear, I started out with some 2x20 workouts and pretty much died, which was expected - but I turned it into a 60 minute workout. 20' @ HardAsBalls RPE, then 20' at a much more manageable pace, and then 20' at the same effort. Is there any structure to a 2x20 workout or is this basically it?

Get Trainerroad. Get faster and never be bored again.

http://www.trainerroad.com/

Excellent. I went ahead and checked out the website and signed up already.

I don't have a pain cave like you guys do, and I don't have a fan. But I do have an open roof with a hose on it. And if that fails its a tropical country so, I guess I can cool myself and wash the bike at the same time.

I think i'll start off with 1 hour rides Tuesdays and Thursdays to replace my 40km evening rides. I have no problem going straight into the suffer zone so I don't doubt I'll see some great gains since I don't have to deal with road hazards, weather conditions, stop lights, blah blah. Not to mention I save a ton of time since I don't need to change, throw the lights on, fill up the water bottle.

Poking around the website and stuff now. How does my PC receive my ANT+ speed/cadence/HR? Through the bluetooth interface?

It looks quite nice, but WOW, given the fact that power meters are very expensive, tack on an additional 100 bucks for a year and you're adding a quite a bit of money to an already expensive endeavor.

Looks quite comprehensive though. :-)

It's the cheapest highest bang for buck thing you can spend on triathlon improvement, actually. It's not overpriced at all, and if you're using virtualpower (no powermeter), it's downright budget.
Powermeters though are indeed expensive.

Aside from the virtualpower aspect (no powermeter needed), it's one of the few things in triathlon other than direct coaching than actually TRAINS you to get better,and appropriate to your ability. If you slack off, you see it right then and there.

I will add for any that are interested, that I just try veloreality's free download software, and it lets you make workouts (very easily) and control a trainer like the Kickr (as well as virtualpower curves for fluid trainers) so you can actually get a lot of Trainerroad functionality for free - but you will miss all the premade workouts, and social features (like seeing how many people suffered through ISLAGIATT) and plans, so I think TR is still worth the money, but if you are like me and both need and want to do a block of all-self made workouts (and thus don't need the library), you can do it for free with the veloreality download.


Link
http://veloreality.com/products/trainer-software/

BTW - DON'T get a fan - get a heater and embrace the suffering in true Sufferlandrian style!

^^^^This
I'm quite poor by triathlon standards so I thought that $10/month seemed pretty cheap in comparison to 1000 bucks for a power meter. Maybe maplesyrup doesn't realize you don't need a power meter with trainer road?
And I made huge strides by using TR with sufferfest for a few months. Its really a huge bang for your buck compared to just pedaling away with a video or even a workout. TR keeps you from cheating yourself. Its amazing how much an RPE of 7 feels 5 minutes in compared to 45 minutes in. No way you'd hold the same power without that damn red bar reminding you how far away you are.