I have to create a collage based on Roll of Thunder, Hear my Cry. Do you have any ideas of images that I could use?

Well, I think with a question like this you have two main
approaches that you can adopt. You can go through the novel and pick out key scenes that
you feel are important and use them for your collage. One scene you might want to pick
would be when Stacey and his siblings plan to make the bus for the white kids stop by
digging a ditch and waiting until it fills up with water. Another might be when Cassie
is forced to get off the path and into the road by Lillian Jean's father. Any of these
moments would provide a clear visual description that you could use as the basis for
drawings in your collage. Take the way the bus stops, for
instance:

But
instead of the graceful glide through the puddle that its occupants were expecting, the
bus emitted a tremendous crack and careened drunkenly into our trap. For a moment it
swayed and we held our breath, afraid that it would topple over. Then it sputtered a
last murmuring protest and died, its left front wheel in our ditch, its right wheel in
the gully, like a lopsided billy goat on its
knees.

Picking out important
scenes like these that make up the key elements of the plot would be a good place to
start.

Your second option would be to consider how you
could represent the key themes of the novel more metaphorically, through focusing on
symbols and motifs. For example, an obvious theme of the novel is the way that racism
impacts the lives of the Logans. Trying to work out how you could express this
thematically through pictures would be a much more interesting and novel way of
completing this assignment. Hope it helps and good luck!