You see Times Roman and Arial
>(Helvetica) recommended most often as these are indeed very clear and
>legible typefaces - especially at the resolutions used for computer
>screens.  remember however that when you print text you are getting an
>order of magnitude increase in dots.

From a designer's point of view:
The design of the font itself is not the only criteria. Lots of other
design issues do matter, as the leading, the width and spacing of the
letters,  contast of background and text, even the paper you used for the
printout (glossy or not) and others more. If you are not sure, it would be
best to ask a designer, who is specialised in exhibition design to advise
you and make templates you can (and should) then use all over your
exhibition.

 This makes some other fonts that
>don't look good on screen much more readable.   I don't think that there
>are any hard and fast rules, except - be consistant. - chose one face for
>headers and one for body text at most.  After that you have to look at the
>image of the institution, modern or traditional etc.

I couldn't agree more. In most cases people choose Arial and/or Times for
their CI , because it is accessible anywhere (on their computer as well as
in the typesetter's shop and at the local Newspaper - this was the reason
why Times was chosen for the CI of Barcelona Olympic Games). There are lots
of typefaces available and I'm pretty sure that most people couldn't spot
the difference between some of them, so better depend on tests with
printouts of typefaces than on recommendations like this.

Kind regards,
Monika Gause
mediawerk hamburg (Germany)
http://www.mediawerk.de