On the day my does are due, typically day 30, I check on them every few hours. When I go to check, I can usually tell if they aren't going to start labor for a while, if they are going to start labor soon, or if they are in labor and about to kindle.
When a doe isn't going to start labor for a while, usually two hours or more, they are just lying down, maybe eating or drinking, or just playing with toys. The babies will be moving inside. Once the babies prepare for labor, they don't move or kick.
When a doe is about to start labor, within the hour, she will act a bit more frantic (now keep in mind labor hasn't started yet), she might jump in and out of the box, be unable to get comfortable (lie down and then get up again), or just hang around the box and keep checking it, or hopping up on it.
Once labor has started, which is characterized by massive fur pulling, and it is a veteran doe, I usually try and stay to watch. But if the doe stops pulling fur while I'm there, or seems a bit more nervous, I'll leave and come back in an hour to see if she's made any progress.
Typically once a doe has started labor, it'll be 45 minutes to an hour before she hops in the box and starts to kindle, assuming everything is going well. A healthy litter of 6 babies usually takes twenty minutes for the does to deliver.
Can the other rabbits tell the doe is in labor? Do they thump or are they quiet?
They can definitely tell something is different when a doe starts nesting, and starts active labor. There's typically an air of quiet. Some does will actually think they are having babies too, so they will pull a little bit of fur from themselves. Some does get more hormonal because they want to breed and have babies. I've heard that right after a doe kindles is the best time to breed another doe, because her hormones are telling her it's time to have babies!
All of this pretty much applies to the majority of my does - the ones that know what they are doing and kindle perfectly. But actually MOST Holland does have no idea what's going on and do very badly during labor and birth. I have been extremely lucky to start with great mothering genes in my first brood doe Gracie. She's really the backbone of the great mothers in my herd. But I think it also has a lot to do with your relationship with the doe. If she trusts you and knows what to do, then most likely she will do a good job. Of course sometimes they are just unprepared and do badly though, and it's totally out of your control.