Let me be the first to say: Welcome to Mudcat, ChancesMom!

If you're trying for a bonding experience where the three of you play music together, you'll have to give up the idea of sharing one or two guitars! Each of you should have an instrument. (Maybe they don't all have to be guitars! The bass and the ukelele each use four of the guitar's six strings, tuned to the same notes as the guitar's "standard tuning".)

The best way of determining which size will be most comfortable for each of you: each of you should "try on" several different sizes at guitar shops. Note that I said "shops" (plural); if you live in an area that has more than one, visit them all. If not, you should be able to have guitars sent to you by sellers on a trial basis before agreeing to purchase them. I think it goes without saying that a left-handed guitar would be most comfortable for your son; most likely, you'll have to order one, but your son can still get an idea of what "fits" his body by holding and strumming a right-handed guitar.

Have you considered renting, or perhaps renting-to-buy, as a way of determining which instruments are comfortable for your family, before making the final commitment to buy?

Do NOT try to cut budgetary corners by purchasing a cheap guitar. It will not sound right, it will have flaws in workmanship that will frustrate you during the learning-to-play process, and it will lessen your enjoyment of the playing experience. There are several fine "mid-range" acoustic guitars, for which you should expect to pay something in the $300-to-$700 range (for a new one). You are correct that you can often get a better-quality guitar for a lower price by shopping for a used instrument (and you'll cry less when it gets scratched if there are already scratches on it!).

Ideally, if you're looking for a guitar you will keep for years, you should avoid any instrument that is made of laminated wood (top, back or sides). Not that the laminated woods wouldn't last for years or anything, but as you become more proficient a guitar player you will become more aware of the sound your guitar makes, and solid woods will not disappoint (and will most likely improve the tone of your guitar as they age!).

Brands I recommend include Martin, Taylor, Guild, Larrivee and (not as enthusiastically, but it's still good for a beginner's guitar) Dean.

I'm not sure why the music-store guy was insistent about separate lessons. Beware -- he may simply be trying to make more money from you than he would make by offering you group-lessons! Talk to a bunch of other teachers, and ask friends to recommend a teacher, before signing on with one.

Good luck!!! Please let us know what you decide to buy, and keep us posted on how the lessons are going!

Sharon