The best online source to start researching these question is probably David Chalmers's website:
http://consc.net/chalmers/

You might find this website interesting too:
http://www.macrovu.com/CCTGeneralInfo.html

My favorite piece of actual science that seems to be about consciousness is the mirror test. All theorizing about consciousness (e.g. Chalmers) can safely be ignored, IMO.

Experimental tests aren't about consciousness, they are about behavior and brain activity.

Even if sufficiently precise theory of brain operation will be devised (which will allow to predict e.g. after-stimulus train of thoughts, introspective thoughts, description of qualia given pattern of neural activity etc.). I think there still will be philosophers that will see explanatory gap as the theory doesn't explain how it feels like (for them?) to be experiencing this stimulus or process of thinking.

Thus hard problem of consciousness seems to be scientifically undecidable, at least in current formulation.

Leaving philosophical considerations aside I myself am inclined to favor representational theories of consciousness, e.g. SMT, as they allow to put consciousness in evolutionary perspective as one of stages of development of central nervous system's representational capabilities, where it [CNS] becomes capable of representing a part of its own internal state in the form that allows to store, recall, communicate and modify parts of internal state in ways aren't possible without explicit representation.