I'm new to Node.js and coming from the Rails world, I'm fond of the ActiveRecord pattern/framework it provides. Is there anything like it for node? Or am I stuck with building queries? Also, Postgres is my database of choice.
Have a look at Tower.js. More of a full stack framework built on top of Express.
The closest thing to a Rails-like framework in Node that I'm aware is Express http://expressjs.com/
Railway.js is like padrino, a full stack modularized framework for Node.js. Tower.js is inspired by Rails so, it's closest match.
I'd say Express is more in tune with Sinatra than Rails, It offers view-rendering engine and url routing basically.