is this a good bike? I haven't ridden a bike in many years. I am looking at this Trek bike, but I'm not sure on the model so I can't look up any info on it. Can anyone identify it for me please? And also, let me know if it's a good bike to start off with? The guy said it's in excellent condition, and ready to ride.
It is a women's Trek bicycle, i can't read it from the image but the model is more than likely one of those teal words on the frame. Google Trek and then those words and look for an image that looks the same.

More than likely basic components but if the price is right and you like it a bike is a bike. If there is rust on the chain or crankset it is not in "excellent ready to ride" condition for someone who does not know how to service it. 

Trek is a reputable brand but that appears to be a low level model, not that there is anything wrong with that. There should be a serial number on it, possibly the bottom of the frame by the crank, that may also lead you to find the model and year if you then search that serial number.