Look at the sticky in the General Discussion forum for screens hits and interpretations thread. You can scan through that thread and pick up quite a lot of good info there.
As for where to put it, that's easy. You want side imaging at the console. The boat has to be moving at a decent speed (1.5mph+) in order to get a pretty clear picture on side imaging and down imaging. Less than 1mph is a bit "blurry" and less than .5mph is definitely blurry and sitting still is nothing but a blur.
That's for both down and side imaging.
So I use side imaging all the time on the console. I have an HDS10 and I have 4 screens showing gps, sonar, side imaging and downimaging. I can switchaikovsky to several screen views I've preset and I use side imaging to locate structure, bait, or large schools of fish. I rarely see bass on side imaging. It's just harder to see them unless they have some good size to them. If they are suspended and big, I can see them but I'm usually scanning 160ft+ out both sides so they look like dots. In shallow water at 50-8ft out, yeah, you can see them better.
If it were me, I'd use your old graph for primarily sonar and a GPS map on the bow for your existing waypoints and side imaging on the console to locate "stuff" and to give yourself a bigger view of a map or sonar when at the console.
I won't say I never use side imaging on the bow because I do. But it's usually when I'm moving to new targets along the bank or just trying to"find some fish" in an area without having to crank the big motor and move around.