I'll be entering the US soon with my family. I will be on an O1 visa and they will be on ESTAs. When I've travelled solo there is always a different line for the ESTA and for those entering on a different visa. Should we as a family stay together and go in the other visa's line or should we go through separate channels?
The general instructions for foreigners are that all members of the same family should go through immigration together.
The exact situation depends on the airport you're entering through, but generally visa holders and first-time ESTA users will all be directed to the same queue - in which case you should all go to that queue.
If they have previously entered on ESTA, or if first-time ESTA users are directed to a different queue, they will still be able to go through the "visitor" (ie, visa) lines, so they should still stay with you.
The airport staff may attempt to direct them to the ESTA line, but if you simply point out that one of you has a visa then there will be no issues at all.