So I've been invited to play pathfinder for the first time, and although I do have previous experience playing 3.5 it's been a few years (half a decade now?). I'm interested in creating a necromancer and based off what I've read so far my best option seems to be making a sorcerer. I'm torn between an undead bloodline and the dragon bloodline. My feeling is dragon bloodline, since I like the idea that his mother, who abandoned him to his father, was a dragon. My fluff behind the character is that he is the 8th son (and a bastard) of local ruling king. He had tired of the intrigue of court and left one night to pursue his innate magical talent. His father the king had forbade he pursue it, so of course he wanted to learn all the more.
What dragon would best fit his necromancer pursuits? Being that he was abandoned, I feel like black dragon would be a good fit, and they tend to appreciate rotten things, but I've not been able to recall an example of a dragon of any type that has a proclivity for necromancy, despite all dragons being casters. Does anyone have a bible/encyclopedia of dragons that might be able to shed more light on a necromancer dragon? I'm aware of the concept of a dracolich but it doesn't really fit with my background at all.
Also, any other helpful ideas to build my necromancer/dragon disciple, such as feats, spells, etc. would be awesome! Thanks in advance for the help.