A lot of research in the digital humanities is done in groups. Here is a short guide to getting things done in groups. This was written for students in my classes.
Discuss how you want to work together as a team explicitly. Ask yourselves how you will deal with people not doing their share.
Develop a charter or short email agreement about who will do what and what the penalties are for those who let others down.
Agree on the collaboration tools you will use.
Discuss how you will communicate.
Discuss the risks of the project, including the collaborative risks.
Take the time to get to know and trust the others.
Designate roles as in who will convene meetings, who will chair them, who will write notes, and who will submit results. Try to make sure that there is someone clearly responsible for every major task including submitting the final paper/proposal/project etc.
If the group is big enough, choose a project manager.
Make sure you are meeting (online or F 2 F?) regularly and checking in on the project. Once a week works for a lot of projects, but you should accelerate check-ins when you get closer to the deadlines. Formally schedule the meetings and make sure everyone has them in their book.
After meetings someone should circulate action items in some way (what is your communication tool of choice?) Then I can check, before the next meeting, what I was supposed to do.
Have an agenda for each meeting, even if the agenda is developed as the first thing in the meeting. Agree on what will be discussed and then stick to it.
Don't let meetings go on too long. Have separate social gatherings for the getting to know each other.
Plan to take stock every once and a while. Find some natural milestone and use that take stock about what has been done and how it has been documented.
Celebrate the project progress periodically. Go out for pizza together or organize a little party.
To do when someone doesn't look like they are going to do their part.
Try to catch people who are struggling early. If someone misses trivial deadlines early or if they don't attend meetings then you should check in on them. Show that it matters and that others noticed.
Send them an email noting that they missed the deadline and ask when it will be done. Be forgiving and negotiate deadlines.
Call them if you are desperate. Ask for a meeting.
If it is a recurring problem then invite them to suggest how things can be done better or how you all can support them.
If it continues to recur then take it up a level. Inform other stakeholders.
If needs be, then ask to drop the person and let them do their own project.
Always be gracious and don't make it personal. Assume they have good reasons. Talk about consequences rather than persons.