I may have misinterpreted what he wanted, but if you're asking 'how do I learn to hack', it's a whole different question than 'how do I learn to write mediocre web applications'
If your goal is to learn to build rails sites, start with rails; however, if your goal is to be good at programming and subsequently be able to build things that other people can't, in the sense of PG's hacker advantage, then you should learn to hack, not build rails apps.
If your goal is to learn to build rails sites, start with rails; however, if your goal is to be good at programming and subsequently be able to build things that other people can't, in the sense of PG's hacker advantage, then you should learn to hack, not build rails apps.