I have a 2004 Ford Focus zts that I just changed the rear drums and pads on. Everything went together smoothly, but now my drivers side is smoking, and I can smell the brakes burning.
I changed the drums, pads, and the hardware on the rear axle.
You obviously have a problem with the rear brake at this point and you should NOT drive it in this condition as you could cause additional damage or even cause a fire.
I suspect you didn't get the brake shoes installed or adjusted properly or the actuating cylinder is sticking. Either way now you have probably cooked the brake fluid and will need to disassemble the cylinder and, if possible, rebuild it, or replace it.
It's important that the wheel turns unhindered after a shoe change and you should position the adjusters so that the shoes are just short of rubbing on the drum. The adjusters are triggered by braking in reverse and so a few reverse start-stop cycles should get them where they need to be.