Take Your Time.
And I mean, really take you time on this one. do some investigative work online and find a convenient bow shop that carries a good selection of bows and will allow you to shoot from that selection.
shooting a bow at first is difficult mainly because you are not used to using the particular muscle groups needed to draw a bow in your day to day activities. you will quickly over come this and find you can draw more and more weight. so it is important that you select a bow that allows you to significantly increase weight as well as a couple inches of draw length in either direction and feels comfortable to shoot throughout the shot.
My daughters have indicated that they want to have a go at archery, so I am right in the middle of what you are seeking to do. I also got my son into archery and deer hunting last year. after he practiced with my old bow and showed he truly had an interest I bought him a hunting bow. See Below Link...
You asked if there are any lines to disregard and why, the best answer to that is to look into how the manufacturers take care of their customer after the sale. most reputable bow manufacturers make at least an OK bow, and I would not recommend emerging companies till they have been out and proven their worth for a few years.
I myself am partial to PSE and even more so now having gotten my 2010 AXE back. they gave me a new set of 2011 cams NO CHARGE.
I have heard of other companies charging $80.00 just to look at the bow. and then an arm and a leg to take corrective action.
I have included a link to at least get you started. good luck! Main Line Bows, Stinger 3G