You will find the Genesis to be difficult. If you are doing this for school, you will probably be expected to write all the code yourself, so the fact that the Genesis is already emulated will have little effect on lightening your load. The Genesis has 2 different CPUs, a fairly complicated video processor, and a non-trivial sound system.
I'd recommend using C or C++ (if you really must) and trying something easy first like the Sega Master System, NES, or a simple arcade game like Space Invaders. There are lots of emulation how-to's out there, I suggest taking a look at the "Arcade Emulation How-To" if you can still find it. I think even Marat Fayzullin had some good basic info on his page.
> I'm new to this area of emulation and was hoping someone could clear some things
> up for me.
> How exactly do I go about writing an emulator, I understand I need to first
> emulate the chips of the system I will be emulating. I'm not gonna be stupid so
> have opted for something along the lines of the Genesis. All the chips for this
> have already been emulated to my knowledge so what exactly comes next?
> Advice on what steps I should follow to construct an emulator would be cool,
> also advice on what languages I should be looking to use. A reasonable time
> frame for the project would be good also and a level of difficulty. I'm looking
> to do it as a 3rd year project in University and have 9 months to complete a
> large project.