The cutting list and an example board layout is as follows. I've used 9mm ply but if you have a different thickness that isn't an issue as all the joints are external butt joints. This is a rough box build not cabinet making.
2 x 25cm x 20cm for base and lid
2 x 10cm x 25cm for hinge side
1 x 25cm x 2 cm for rear lid
1 x 25 cm x 18cm for rear base
2 x 20cm x 20cm for sides (these will each be cut into two to make the lid profile)
If you have access to a table saw these are easy to cut up and some wood stores will cut these up for you if you ask, usually for a small charge. They are unlikely to cut the lid profile though, that you will probably need to do yourself.
Have a piece of sand paper on hand and lightly sand off any cut edges to prevent splinters, sometimes the cut is clean, but its no fun picking bits of sharp wood out of your fingers. Ultimately I intend to varnish these boxes which will help prevent further splinters.
I've done two lid profiles. Being a project box, the idea is that all the project stays inside the box, so the lid will hold the assembled electronics, breadboard etc, and the base will hold the power supply, meters etc as well as the loose components. As the breadboard needs to be easily accessible, the lid profile has to facilitate easy access.
My first profile was a straight diagonal. I'd already decided that the edge of the lid would be 2cm, so it was just a case of cutting a straight line across the side pieces from 2cm down to 10cm down and job done. This is easiest to do but does mean that the sides can encroach on the access to the breadboards. The second lid profile is curved, with a low front which then curves up to the rear. I actually like this profile better but it takes more cutting effort. The curved profile was measured by drawing a centre line across the side panel and then using a can to give the curves.
The straight diagonal can be marked on the wood and cut straight across, either with a hand saw or a power saw.
The curved shape can be cut with a fret or coping saw, but I was able to cut it with a power band saw. For the curved line, printing it out on paper and transferring the profile to the wood with pencil before cutting works well.