I think you should also learn how to do vectorial inking, Mariana. It's easy to do and InkScape makes it all the easier. Once there, you can color and shade quite easily. See example, it's kind of half-assed but it's what I could do best:
Inking andshading with vectors is quite easy and fast. You can control the type of stroke you want, and shape the shades as you'd like.
@Dannae: I never said I wanted black with H, silly ;P I just said that 2B aren't the Holy Grail of shading, useful for everything. But yes, you can only get true black with soft pencils.