To determine the size of your speaker boxes you got to have the speaker drivers. For the material of the speaker box best use MDF, it's heavy but relatively cheap and it has a high level of density which makes it perfect for speaker boxes.
You also need some screws, nails (optional), glue, a filler to stuff the box with (like polyfill) and silicon to seal the edges.
For tools you need a saw, screwdriver, centimetre, a drill, compasses and a jigsaw.
I split it into two boxes; one for two sub woofer speakers and one for three woofers and two tweeters.
To determine the size of your boxes check the optimal volume and displacement for each driver. For the two 15 inch sub woofers I use a case os 92 by 65 by 40 cm (internal dimensions) For the other case I use 92 by 65 by 30. The MDF I use is 15mm thick.