I'm currently a wildland firefighter for the federal government. Never before have I had a job that I look forward to waking up at 6am to drive an hour to work. If your into physical activity, its fun stuff. Most people don't differentiate between wildland firefighter, and a firefighter.
I went to EVIT, a technical school, for the past 2 years studying structural firefighting and got to do some intense training through that, as well as training with Gilbert Fire Department for the past 2 years. I was offered a job with the Bureau of Land Management to do wildland, and accepted it.
Its not city, but I still love it. Whats fun? I had the job offered to me a week before I graduated high school, and was working the weekend after graduation. Great stuff huh?
Like someone above said, structural firefighting is extremley competitive. For 50 positions, you have 3500 people applying for the position. The only way to ensure your spot is to goto college and get every related certification and class you can. I'm getting my EMT-B in the fall, and will be hopefully be getting my FF1 and FF2 certifications shortly after that.
Personally, if you want to get on, apply EVERYWHERE. Not just the big ones (Phoenix, Glendale, Mesa, Tempe, etc) but everywhere you can (Goodyear, Sun City, Sun City West, Sun Lakes, Apache Junction, Gilbert, Chandler, Peoria, Scottsdale, Avondale, Guadalupe)
Easily, a career in public saftey will be one of the most rewarding you can find.