I'm trying to create a dragonblood beginning sorcerer based on the rules in Manual of Exalted Power - Dragon-Blooded. The background information indicates that it should be possible for a Heptigram student to know some spells by graduation, but doesn't include rules for getting them with bonus points. I also haven't come across a dragonblood equivalent of the able-to-do-sorcery charms that other exalt types have. Are there creation rules elsewhere for making a dragonblood sorcerer? And if not, how should I handle this?
The Dragon-Blooded can do Sorcery by taking the "Terrestrial Circle Sorcery" Charm. It is on p134 of the Manual of Exalted Power - Dragon-Blooded. It is the same than the one for Solars, on p220 of the main book. Note that they cannot take higher Sorcery Charms than this one.
As for the spells, this is actually described in the main book Character Creation chapter, on p75:
Characters who know one or more Sorcery Charms (derived from the Occult Ability) can begin the game knowing spells. Characters can exchange a Charm for a single sorcery spell but may not start the game with Solar Circle spells (spells of the highest level). Characters who wish to purchase spells with bonus points pay the cost for a Charm. Characters receive the in-caste discount on spells if Occult is a Caste or Favored Ability.
This works the same for Dragon-Blooded characters.