Me wrote:

I had a new back door installed at my house, It is a full masonite door.

I've never bought this type of door before. Now that it is hung, what do I
need to do before painting? (It came unpainted)

Does it need any type of stain on it, any weather proofing? Anything I
should know about this type of door?

Thanks

http://www.masonite.com/PRODUCT_GUIDE/catalog.asp
Left menu under "Entry Systems" - 'Fiberglass Staining Instructions', a
PDF file.