Adjust png 'page' for bleed

To scale your images (expand them into the bleed area) click one of the sizing handles (little boxes on the corners or at the center of each side) and hold down Ctrl + Shift (Windows) or Cmd + Shift (Mac) as you drag to expand the frame.

You are goint to lose some of your image on the edges after trimming. If you need all of the information tht is in the 8 x 11 image you will need to edit in Photoshop or other image editor to add canvas area and mor image around the edges. An alternative might be to shrink the image slightly on the page and use a colored background frame that extends to the bleed.

(Briefly) Set up a New InDesign document (see screenshot) adding the number of pages you want, then Place and drag the images on the page ensuring the depth or width reaches the bleed marks. (pressing W with nothing selected will hide/show the margin lines). You can experiment with Object > Fitting  to see the kinds of fitting.

Ensure in the Links Panel the Effective PPI of each image is around 300PPI. Ask the printer what format they want the document supplied in – PDF, JPG or PNG.

Select File > Export and choose the format they want from the dropdown menu.