Well, raking is a good choice for a character with long claws. Much like many different wild animals, they’ll come at their opponent open handed and drag their claws down across the face, use them to slash at the exposed throat.
Here’s something to think about when working with a character who uses claws. Punching isn’t really going to be feasible for characters with non-retractable claws. If they are long and sharp, then when the fingers curl into a fist, the nails may puncture the flesh inside their palms. Depending on how long and sharp the claws are, making a fist may not even be possible because they may not even be able to safely make a fist without harming themselves.
Take a look at styles that focus on open hand attacks instead of fists, joint locking disciplines like aikido, jiujutsu, and the variations of chin na that apply to different kung fu styles (shaolin/tai chi chuan) as a different way the character may fight.
I’d also suggest taking a look at nature documentaries, particularly for lizards and big cats. When looking into lizards, especially large lizards, focus on tail-whipping. Many lizards will use their tail as a weapon when they feel threatened. I’d check that out.
References and Reading:
Highlander (The Series): While I can’t really recommend the sword combat (at least in the early seasons), Adrian Paul has the distinction of being skilled in aikido and his martial arts during the series is very good.
White Wolf’s Changing Breeds, Nagah, and Mokole: These changing breed supplements to Werewolf: The Apocalypse are interesting because they focus on weresnakes and werecrocodiles. They might give you some ideas. They aren’t common, so they may be difficult to find.
Nature Documentaries and books. Pick an animal, or even a few different animals to build the character’s combat style around. Get to know the animal, check out books about them from your local library, study how they hunt and how they behave. It might give you some ideas.