Simple collections of serializable types should serialize correctly.
Arrays (float[]), and Lists (List<float>), are the two supported collection types.
Multi-dimensional and jagged arrays are not serializable. See other collection types below.
Dictionaries are not serializable, but you can implement ISerializationCallbackReceiver to manually serialize a dictionary into serializable datastructures. There's an example of that structure in the documentation.
There are also SerializableDictionary implementations out there that are wrapper classes that implement the interface, and may also have a custom property drawer.
You can implement ISerializationCallbackReceiver to manually serialize these types, but it can add unnecessary complexity to your codebase.