[perezda]

Start with the Stanford course. It's the best free resource out there. Find a local meetup. Go to a couple hackathons.

re: other comments -

Apple's docs aren't great, in fact I hate them. Haven't put my finger on why.

I like some of the controls at http://cocoacontrols.com

I wouldn't start with Arc. Especially since you're comfortable in C.

[BenSS]

The apple docs are pretty comprehensive. I think of it as you're not going to learn English by reading a dictionary.

The specific example apps that apple provides that demonstrate one particular thing are great though.