There are four of us in our two-bed semi. We've had our house on the market since last year, unfortunately no one seems to be interested in viewing, let alone buying our house.
The kids (18 mos & 3 1/2yo) share a room, while we have the other. At the moment we have a cot and single bed in the kids room, but if we're here in a year's time it may end up changing to bunk beds. We have the main computer in our bedroom, as DH often works from home (it used to be in the kitchen when DS's cot was in our room).
We have a drop leg table as our kitchen / dining table and a sofa bed in the kitchen to give more room. We also have folding chairs to save space. The cusions for the folding chairs get used to line the wall at the back of the sofa bed to protect the walls and little heads from bumps.
My advice:
Find multi-functional furniture that can help save space.