This is a favorite with Feral Liberal, and for all of you I am citing a website you can go and get all the information about grosbeaks you will ever need; http://birding.about.com/od/birdsgrosbeaks/Birds_Everything_About_Grosbeaks.htm
Also, there is a wonderful series of pictures at http://birding.about.com/gi/dynamic/offsite.htm?zi=1/XJ/Ya&sdn=birding&cdn=hobbies&tm=78&gps=83_9_1020_583&f=00&su=p445.92.150.ip_&tt=14&bt=0&bts=0&zu=http%3A//www.wbu.com/pics/liferbgr.htm.
Rose Breasted Grosbeaks are not something I see here in N.TX. and in fact my only sightings were in Maryland, in a thicket area, taking a walk just to bird. But I recommend it highly.