Fortunately indesign cs5 makes these changes easy.
Indesign viewing gutter lines.
Here is an example on an a5.
Indesign uses the first definition in margins and columns so i m going to guess that is what your question is about.
The problem is that my margin gutter grid lines only show up behind the image this makes it really hard to place text.
Enter values for top bottom left and right margins as well as the number of columns and the gutter the space between columns.
If you accepted the defaults for page orientation and size margins columns and gutters when you created your indesign creative suite 5 document and then find that you need to change them you are not alone.
You can create two kinds of ruler guides.
Create a spot rgb swatch to denote fold lines in the slug.
Page guides which appear only on the page on which you create them or spread guides which span all pages and the pasteboard of a multiple page spread you can drag any ruler guide to the pasteboard.
Open the pages panel window pages and select the thumbnails for the pages you wish to change.
Assuming i guessed correctly are you trying to define the gutter widthor gutter position.
Ruler guides are different from grids in that they can be positioned freely on a page or on a pasteboard.
Make the margins twice as thick as the gutter place a ruler guide in between.
Use margins and column guides to position content.
Choose layout margins and columns.
Page orientation and size when you create a new document you can.