What printer are you using? What is its actual resolution? What do you
intend to do with the 'slides' that you produce? What size image do you
expect to get?

Look at the enlargement that you get from an overhead projector and the
quality of image - then think about the extra enlargement that you might
typically attempt from the far smaller 35mm format. Is the quality good
enough for you?
I cannot believe that you wouldn't be disappointed with the result.

No problem - just like any other image manipulation.

I doubt if there would be a specific tutorial as I don't believe anyone
would do it. The exercise needlessly reduces the quality of image by
many-fold. Why not produce OHP near-A4 slides and have far more reasonable
quality?

Off the top of my head, I think that http://www.fotoserve.com prints
slides. I may have that URL wrong...

Alternatively, depending on the use they're intended for and whether
they need to be perfect, I've had reasonably good results with taking a
photograph of a computer screen. Cost = slide film & developing.

Obviously you're limiting your maximum resolution to that of your
monitor, but it's cheaper than hiring a video projector!

The only thing to be careful of is using a slow enough shutter speed
that you get plenty of screen refreshes in, otherwise some of the screen
will be brighter than the rest. 1/8 always worked for me.

Far better to print them to A4 size on decent quality paper and then
photograph the print. Use Velvia and you'll get better quality than is
possible with most other methods.
Or as Simon suggested, photographing the screen can give pretty
reasonable results.

You can buy a special 'printer' called a slide-writer: excellent quality,
but not cheap.

Quite a few lab.s used to do this too, I haven't had it done for a long
time, but some years back I had Sky Photographic make up a set of 35mm
slides from files I gave them on disc, and they were  _very_  good.  They
might still do it.

Either way will be vastly better quality than you'll get by using an inkjet
and transparency film - though I can see that being fun to experiment with.

Peter