Now thats something I'd like to know more about!! I have really, really oily long thick hair though...
No problem clover! It works on all hair types. My hair is naturally very thick and wavy, and it worked great, then I got dreadlocks and it works great on them. I've spoken to people of all hair types who said it was great.

The method I was taught is to put a small amount in your palm (you'll learn how much is enough for you personally as you go along) and mix in a few drops of water to make a paste. You really only need to scrub the roots and as you rinse it out it washes the lengths of you hair. Some people dilute the bicarb with a lot of water and use it like a rinse, personally I've felt the paste method is best for me. Obviously make sure you rinse it well so there's no bicarb left in your hair.

Then you dilute a small amount of apple cider vinegar (usually a teaspoon or two, again your own personal experimentation will teach you how much is the right amount) then dilute in about a cup of warm water. Then pour over your hair.

Can't recommend it highly enough! There should be more info around the net on this, it's called the 'no poo' method.