I ate this in Barcelona with my mom, it's a beautiful dish with a subtle but rich flavor.

 I had my doubts about this recipe the way it's written.

I think the intent of the initial sauteing is to end up with a nice thick caramelized sofrito.  Mine was a watery soupy mess with little color and not much flavor.  I was worried about overcooking the squid.  Next time, I would do things the right way: cook the squid first, remove it, cook the onions, then the garlic, then the tomatoes.  And really who is going to GRATE two tomatoes?

3 cups of paella rice is a LOT of rice.  The whole point of bomba rice is that it can absorb 3 times its volume in liquid while still remaining firm.  So I reduced the amount of rice to less than 2 cups, which was plenty.  I had a hard time finding fish broth, so I used 2 cups of canned broth and then a bottle of clam juice and water.  I think some white wine or sherry would not go amiss in there.

Squid ink is sold in packets of 4 grams. Experimentation showed that each packet is about half a teaspoon... so 2.5 teaspoons would be about 5 packets. Even though I used a good quality brand and the recommended amount, my rice did not come out all that black.  Next time I'd add it earlier in the process.

This recipe seems more realistic, except for having to extract your own squid ink:

http://www.nytimes.com/recipes/5307/Rice-With-Squid-Penelope-Casas-Arroz-Negro.html