folded greeting cards

Well you start off by - not being funny here:

Get a pencil and paper, and fold the paper the way you want it to look. Pencil in some sketches of text and image placement.

Unfold the paper, then recreate what you seen when it's UNFOLDED, in InDesign.

When you fold a greeting card you will have 4 sides

Front

Inside Front

Inside Back

Back

So on your page you should have

Back|Front

Inside Front|Inside back

If you want the greeting card to be A5 when finished (210 (h) x 148mm (w))

then start with a A4 sheet of paper - turn it so the long edge is facing you.

Then fold it in half horizontally.

When you make your indesign document

Make it 210 mm(h) x 296 mm (w)

Then draw a vertical guide with the ruler (CMD/CTRL R to toggle the ruler)

Draw the guide at 148mm (in the middle of the page.

At this point you'll need to make sure that nothing is too close to the fold, so draw another guide at 138 mm and another at 158mm

Then keep text within the Blue and Pink lines.

If you have any images that require they are at the edge of the paper - ensure that you extend the image past the page edge by up to 5mm.

See this thread on bleed (http://forums.adobe.com/thread/721057?tstart=0)

The rest is up to you.

Best of luck.