B.W.
I have very curly hair, but its not very frizzy, just ringlets. But if I don't take care of it, it would be frizzy.
Avoid products that say 'for dry hair' because they will contain waxes and that will over time build up and make your hair WORSE. There are some that I've had good luck with, but try to avoid taht for the most part.
Only shampoo every other day, or ever two days, but condition every day. SAy on Monday I shampoo and condition, but on Tuesday I only condition in the shower, and weds I shampoo and condition, thurs I only condition, and so on. Shampoo can be harsh, and it strips away alot of moisture in your hair, so if you can go 1-2 days between using shampoo, your hair will be alot healthier because of it.
Watch how you comb and brush. If your hair tends to be frizzy or dry, only comb it when its wet, and use a wide tooth comb starting at the bottom and work your way up. Wet hair is fragile nad prone to breaking, so be gentle. NEVER USE A BRUSH ON WET HAIR! Once your hair is dry, leave it alone. Brushing it will only make it more frizzy and dry. Allowing it to dry naturally will not only allow the cuticle to seal so its not fuzzy, but it'll not expose your hair to further damage from teh blow dryer.
Paul Mitchell products are wonderful, and I really like the Tigi line as well. I don't know much about flaky/dandruff, as I've never had it, but I'm sure if you consulted with a good stylist or salon owner, you would get great information and recommendations.