If you are indulging in any structured training programmes, you really need to test where you are, and what your various training levels are. This is where fitness testing comes in.
Now to measure progression, simply doing a test run on a certain route/climb will often be sufficient (certainly I do this a fair amount), however, I'd always recommend getting a proper test done.
The two main tests out there...
Ramp test. this is where you sit on a rig or trainer and pedal against a slowly increasing resistance maintaining a constant cadence. Continue this until you fail basically. In measuring stuff like Heart rate, watts, gas exchanges (thats the funny mask thing), and blood lactate you can ascertain your VO2 max (the amount of oxygen you can process per minute, per KG of body weight), and the two lactate turn points. This will allow your coach to accurately establish different training levels. By measuring wattage at VO2max you can map progress and improvements. VO2 max is a good indicator of aerobic ability... basically the size of your engine.
20Min test. This is exactly what it says on the tin. You ride on a rig or static trainer again, but this time its a case of you going as hard as you for 20mins. You should do this 'blind' and ideally supervised in test conditions so tis repeatable and you are motivated to get it all out. Again, what this will do is provide your wattage/HR for a 20min effort, which can then be used to calculate functional threshold Power (how hard you can ride for an hour), and your training zones thereafter. It is also a brilliantly easy and efficient way to monitor progression as the test can be repeated cheaply.
Personally, at Koolstof we use the 20min test, and I would recommend it for price and the fact you are physically producing the results that a Ramp test uses science to calculate. I wrote an article on it recently for our coachign site.
http://www.koolstofcoaching.com/articles/training/how-fitness-tests-improve-race-resultsAs for where you can get a test done, I would as a first point of call, get in touch with local universities and see if they have any bike related studies taking place. If so you may be able to get an all bells and whistles test for free! I've managed to do a few with Exeter University.