Reading people can be very difficult sometimes. There's a lot to consider, analyze and look for. The best way is to just talk to them, and hear how they respond. If they're nice and polite (and you do the same as best you can), then chances are that they like you. :3
Though, more often then not it's mere friendliness. Things like romance usually develop over a longer period of time, at least in my experience/observation. ''Love at first sight'' rarely really happens.
I'm on the other end, where I sense very well what people think of me. Usually it's not too bad, but there are some people (about 1 in 5) that just give this dreadful vibe. I find that that vibe is caused by either hate, anger or anxiety on their part.