How do you motivate people to hand something in when they are not employees?

That’s my main question, but there’s lots of other questions that go along with it. Here’s the deal…

So, for those of you who don’t know, I work as a Church secretary in the office. Yeah, I could say I’m an administrative assistant, but I’m not so full of myself that I can’t just say I’m a Church secretary. Anyway, twice a year we have a new member class for people that wish to join the church, and twice a year, I face the same problem. When people join, on the Sunday that they are joining, we have a new member booklet which is basically an 8×11 folded booklet that has each person’s photo, or, if it’s a couple joining, a photo of both of them.
We also include a bio that they write up about themselves. Maybe they only write one paragraph, maybe they write five paragraphs; we pretty much leave that up to them.

The frustration comes in on my part because, since we need to have the booklets ready for that Sunday, and because I can’t just snap my fingers and have the books compiled, printed out, and folded, we have to put a deadline on when people hand in their bios. Even though we give them a reasonable deadline, we still have to gently nag them to send it in, and then we always have some people who don’t meet the deadline and literally send their stuff in at the last moment.

So how do you handle this? I am having a meeting with my boss tomorrow to talk about this, but I really value people’s thoughts on here. Obviously there can’t be any kind of penalty, like there might be if this was for your job, and we wouldn’t want to go that route anyway. But it really ends up being a source of stress for me because it ends up falling on me to magically get everything done at the last minute. Meanwhile, I have my regular weekly work to do and at the end of the month I have to publish the newsletter. So it’s not like I’m just coming into the office and working on nothing but these booklets.

So then I started asking myself, why do people take so long to send a bio? And I suspect it’s because a lot of people struggle to write. Not that people are illiterate, but I think a lot of people just struggle to put a paragraph together. So I’m also looking for ideas on how to make that easier for people. One thought I had was to maybe send them out a list of questions to give them a bit of a guideline, and I would tell them to try and answer at least five of them. (They can answer more if they wanted.) I’m even to the point of saying that if they don’t feel comfortable writing it themselves, if they answer the questions in short phrases, I will put a paragraph together for them. I happen to be comfortable writing and I wouldn’t mind doing that if it means that it’s going to take more stress off of myself.

So to reiterate, how would you stress to people who are voluntarily being asked to do something, that they need to meet the deadlines? And, do you have any ideas besides what I mentioned that might make the process easier for them?