Page 1, Page 2, Page 3, Page 4 ... that's the order in which we read a book or newsletter. But is that the way we print them? Not always.
Sometimes pages must be printed out of order. On this and subsequent pages take a look at some simple examples that demonstrate imposition or printer spreads -- the process of printing multiple pages on a piece of paper in such a way that when folded (and perhaps cut) they end up in proper 1, 2, 3, 4 order for readers.
See the first sidebar illustration (click on the image to bring up a slide show of all illustrations) of a simple 4 page booklet printed on letter-size paper (digest size - 2 pages per side) or 4 pages on an 11x17 page (typical size for an 8.5x11 newsletter, for example).
Add 4 more pages to that booklet and your page numbering changes as shown in the second illustration.
Software designed specifically for creating greeting cards often handles the page layout and printing automatically. However if you are using a graphics or page layout program that doesn't, see the third illustration for how you would layout a side-folding greeting card printed on 1 side of a letter-size paper.
Next, look at an example of larger imposition layouts for commercial printing and get tips on saving money with careful imposition planning.