Snapping Images to Margins

[Geobop]

I imported a Word file into my first InDesign project. Now I'd like to go through and resize all the images.

The tutorials I've seen tell you to resize the images (or frames) by simply dragging them by the corner. But is there a quicker, more precise way?

Most of the images will span the page, or that portion of the page spanned by the text. So I'd like to give them a value of 100% (or 100% minus the margins) + centered.

Later, I'll probably change some of them to 50%, 75% or 90% but still centered, while some will be smaller and floated to the right and left.

But to get the ball rolling, is there a quick and easy way to align images with the page margins?

[Geobop]

I've discovered that it is pretty easy to do it manually. I simply grab an image in the center and align it with the left margin. Next, I grab an image in the middle of the right border and drag it to the left. Then I select Frame Fitting > Fit Content Proportionally. This leaves the top and bottom margins of the frame quite a ways from the image, so I simply drag them into position.

This works pretty well, except it's sometimes hard to get an image the correct size to span the page from one margin to the other.