I'd like to print some large A4/A3 sized checklists on paper for people to tick out. Is there any tool that just helps me to churn these out like bullet points in a minute and not have to spend half an hour on things like sizing and formatting?
Tweak Your Usual Text Processor
Why not just change the bullet style in Word to be an empty square? It can be changed to a variety of symbols, including an empty square that would be good enough to be used as tickboxes.
Other WYSIWYG editors can do the same, of course.
For the record, my personal preference for online tools would go to Google Tasks, though I don't really use it much anymore (I keep my TODO list in issue trackers or in plain text files now). The Google Calendar integration can be handy at times as well.
Make an HTML page with
For a traditional program, CNet recommends a very simple software called My Checklist. It has functionality for printing checklists. A word of caution though: CNet (usually a trustworthy source) claims that "My Checklist downloads and functions without issues", but there have been user reports of adware problems.
Evernote lets you create a checklist with almost no effort. Select the checkbox one time, it will be autoinserted on the next line. In effect, you just type the entries. Printing is easy and straightforward.
Another option I've used is to spend a little time up front creating a checklist template in Word or OpenOffice. Once I've invested that time, setting up the formatting, fonts, checkboxes, etc. creating new checklists is quick and easy.
This one is more of a hack, but has been useful to me in the past. Use Outlook Tasks - you can enter each checklist entry as a new item, all within the same category. Print one category's tasks, and if you've picked the print format correctly, it will come out as a checklist.