I sang in a children's choir from age 10-18 and had a fantatic experience, and I want the same for our dd. I think the age to start depends upon the choir. I would recommend age 8 at the youngest for a serious choir (like, not church choir or a homeschooling community choir or something). I think it's important to be able to read so she can learn to read music if she doesn't already and to be able to fluently read words in songs along with notes and be old enough to have a good counting sense for rhythm. Of course, she also needs to be okay with rehearsals and what is expected at performances. Choir is probably the most profound experience of my life--I learned so much about other languages and musicality and it's also where I met dh at age 14 (we're now 29 and 30). As to what to look for, I would go hear a performance and talk to the director. I would discuss rehearsal schedules, performances per year, travel, expenses for attire, parent involvement and expectations (some want you to fundraise), and also whether they require auditions and what to expect if they do/how to schedule, etc. I would also ask how much musical knowledge the children are expected to have upon entering. The best choirs will require an audition. If they don't require and audition, then it may be fine but most likely the caliber of music they perform will be much lower (which may or may not matter). In a perfomance, I would look for these signs of a higher caliber choir: Training choir for younger kids and Performing Choir for older kids (not mixed), a "classical" section with music in other languages such as Latin, Italian, and German, polyphonic music (multiple voice parts) with little unison singing, and just overall blend of parts. The best choirs will also have balanced voice sections (equal or near equal numbers of girls to boys). Also, just get a feel for how the director speaks with your child when you talk with him/her. That will let you know how well your child will work under their direction. It is definitely worth looking into! I hope it works out for you!