What to look for in a Boxing gym?

So, I'm getting interested in learning how to throw hands, and adding some boxing to my Judo skills. There are a couple of gyms here in town that I want to check out, but I'm not sure how to gauge quality of instruction and whatnot. I want something where I'm going to learn some good old-school fundamentals, not something with group boxercise classes and feel-good motivation.

So, what should I keep an eye out for? What kind of characteristics does a legit boxing gym have? What are some tells for an over-commercialized money grab? Do I have to buy anything before-hand, or will showing up in shorts and a t-shirt count?

I'm in the Ottawa area (Canada) if anyone has any local knowledge.