Each association has its own set of rules and restrictions (often referred to as CC&Rs) to prevent individual condo owners from going hog wild during remodels, and potentially impinging on other owners' safety and comfort. Some are stricter that others, but cover things like:
• work to the systems inside your condo, such as ventilation or electrical;
• changes to the structure of the space, i.e. removing walls;
• matters outside, such as parking and dumpster use during construction;
• choices in certain materials;
• guidelines around dangerous pollutants, such as lead paint and asbestos.
In the case of my family's Florida vacation home, I am only doing basic cosmetic changes, which means that no plumbing needs to be moved or walls need to come down. Before we got rolling, I had to fill out a short application, describe the scope of work, and provide our contractor's license number. Pretty easy stuff. As the process moves forward, I am also responsible for clearing the type of sound and moisture barrier I'll use underneath any hardwood floors. Decorating choices are fair game though, so those hot pink cabinets and teal carpet I have planned are all good to go.
In short, the more you change, the more they'll want to know. Ask a bunch of questions in advance, provide what they ask for, get their official stamp of approval, and you should have no worries down the road.