Hi Chris,
I'm currently an air force firefighter posted to CFB Trenton, so I can answer a few questions regarding training, the postings that you can expect, and work schedule. Can't say much about the recruiting process, as I remustered into the trade, but I imagine prior firefighting experience should help.
Aptitude test scores required are the same as infantry, although this may be changing as the trade is currently undergoing a tasking review - which has'nt been done since 1974. This review will be completed in the summer and will most likely result in the trade recieving specialist pay (fingers crossed) and may also change the entry requirements.
Currently we have around 450 firefighters, with an average of 2-3 QL3s going every year. Turnover rate is pretty high as lots of guys get out after they finish their QL5s and get on civie departments, so the chances of getting into the trade are pretty good. Training is excellent - 16 week QL3 course which is a lot of fun. about half in the classroom and the rest is at the burn buildings, ripping apart cars or making entry into the aircraft mock ups. (no driving the big trucks until you get to a fire hall)
Once your 3s are done you will be posted to a fire hall at one of the air bases (Comox, Edmonton, Cold Lake, Winnipeg, Greenwood, Shearwater or if your french, Bagotville) Your QL4s will be between 6 to 18 months before going back to Borden to finish your QL5s.
While at a fire hall you work shift work - 4 days, 4 days off - 4 nights, 4 days off - split shift of 3 days, 3 nights than 6 days off. Sweet.
Once your 5s are done, then the trouble starts. You go to sea, and you belong to the navy for the next three years. Not fun, but ya gotta do it. The good part is you can usually get the coast you want, either Halifax or Victoria. After that its just luck whether you get a good ship with a good crew and a light sailing schedule, or not.
To give you an example- I spent 3 years on the ship and 19 months out of those 36 sailing. A long time to be away from home, listening to fishhead stupidity.
The other thing that is happening is the fire trade is being tasked with becoming the militarys NBCD specialists. The Jnbcd coy just started up in 2002 and 35 fire fighter positions were established there. This is bar none, the worst possible posting in the trade and should be avoided if possible. While at the Coy you are no longer a firefighter, you are a car washer, a ball- scrubber, general labourer, warehouse worker - you are many things, just not a firefighter. Basically your working for the army as a "decon" specialist and have to deal with army BS for three years. Guess where I am.
Right now policy is you have to do 2 ship tours, or a ship tour and a JNBCD Coy tour during your career, other than that you'll be at the firehalls or maybe teaching at CFFA. Be warned though, the fire trade is one of the most mobile trades in the CF so expect to move around a lot (every 2-6 yrs) and sooner or later you'll have to get posted somewhere in the country you don't want to go. Having said that, its also an awesome trade for getting a lot of qualifications from, that are completely transferrable to the civilian sector.
Hope this helps, any other questions just post.