"Proto-feathers" refer to a number of feather-like structures predating the emergence of modern feathers.
It's not that they are "Feathers that aren't really feathers" but rather "feathers that do not have all the characteristics of modern feathers".
Much like a chariot could be said to be a proto-car. It doesn't have a combustion engine, it doesn't have windshield wipers, but from our perspective you can see where the technology ended up.
The first feather(y) structures, evolved from scales.
Feathers actually didn't evolve from scales, though this misconception is wide spread. There was an excellent article demonstrating feather development a few years back in (I believe) Discover Magazine. I'll try to find a link for you.
Feathers, scales and hair all utilitize the same proteins.
A lot of recent finds in China have shed a great deal of light on the development of feathers and flight.
One thing I find particularly telling is the presence of symetrical "wing" feathers on some of the fossils. Symertical feathers can not be used for flight, so obviously the development of feathers was due to some other selective force. Once feathers were in place, flight developed using what was available.
If you google feather, china and fossil, it'll get you started on dozens of article about the recent finds