A little about myself:
I've programmed a couple of tiled 2D RPGs already, using SDL. I'm also familiar with some "advanced" math, like transformation matrices and what not.
On to the problem, then!
I want to create an isometric 2D RPG game, but I have no idea where to start. I'm familiar with the concept as such, but I have no experience whatsoever with the implementation. For instance, SDL has a function called SDL_BlitSurface() that blits rectangles, that I've used to copy the texture onto the map. How I'd do the same with an isometric tile, however, I cannot fathom.
So, where do I begin? I've searched for both tutorials and actual code, but found nothing that left me any wiser.