creating a trifold brochure in Quark. I remember from schooling that 1 of the 3 panels was always a little wider than the others to make up for the folds, but I don't remember what size.
Anyone know where to set up my columns?

Just emailed you a template. ;)

Found more here:
http://www.my1stop.com/BrochuresContents.aspx

Thanks a bunch Nato. You're the man!!

Hey, you're welcome my man!

Generally, divide it by three and allow a 1/16th inch (or less) over hang on the front panel so that it easily lifts open to read it, your back panel will be just a little shorter in width as it typically folds into the center panel. Panels are basically; front=3 11/16", center=3 5/8", back=3 9/16" for an 8.5 X 11" sheet.
I have been in the trade for 30+ years, I have found that templates are okay but their development at times is done by a person with little or no actual application experience.

Qfxc: Those dimensions are way fat leaving you with an 1/8th" of a difference between the front and back panels when they should be equal and align with each other. Only the 3rd outside panel needs to be shorter to tuck inside the front.

As part of the rest of the world, which is sensibly metric, I use 1/3rd of A4 + 0.5mm for front and back and -1mm out of the fold-in 3rd panel.

ie 99.5mm [Front] / 99.5mm [Centre/Back] / 98mm which leaves the outer edges aligned and the inner fold 1mm short. In old imperial (USA) measures you need only deduct 0.04" or 1/25" to tuck in the inner fold. You would increase the difference if it where printed on heavier stock.

Your reference to the back and centre folds of a gatefold brochure as 2 different panels is odd as they are one and the same. If you are making a concertina fold, all 3 panels would be the same width. A good printer can fold quite accurately. It is a simple mechanical adjustment. The only reason to make the front panel wider than the other 2 is to allow for poor folding. I prefer they get it right.