How large are the squares?
You can set up the margins and use the Draw/grid tool or if you want t odo
your own thing:
Use the rectangle tool with the shift key held down to force a square. Copy
it and nudge the 2 together. Group the 2 and copy the pair. Nudge the new
pair together (using the arrrow keys) with the 1st 2 and carry on until you
have a row of 10 built up. Group the lot and then copy the row and nudge the
new row under the first. Continue the process until you have your 10 x 10
grid. Group the whole thing and now you can set it to the size you want by
dragging one of the corner points (holding the shift key down to constrain it
to stay as a square)
Hope this helps
