Another vote for the Brother Cs6000i. I bought mine from Amazon. Good sturdy machine, but too small for me once I really got serious about quilting. I made at least 5 quilts on it though, so I think it's good for beginners. It comes with the quarter-inch quilting foot and an extension table. It has a needle up/down button which is another great feature for piecing.
I gave mine to my niece and nephew (who were 8 & 12 when I gave it to them). They have had it 2 years now and abuse that machine pretty bad and it's still working. It won't last forever (plastic gears) but for the price I paid for it I've been impressed at how rugged it's turned out to be. I know for a fact they've sewn through cardboard with it, LOL. They are able to thread it, change needles and do basic troubleshooting on it.