Connect a generator to a stationary bicycle, by affixing the circular rotation of the front wheel to rotate coils inside the generator. The coils hold wire that have to rotate inside a magnetic field inside the generator or the coils have to be still while a magnet turns around inside. To do this, the bike's front rotating axle must be welded or pinned to the generator's coil shaft. Alternately, you can add a chain gear or pulley to the front axle and the shaft. Then, run a chain or belt between the bike and the generator to allow the bike axle to rotate the generator's shaft.
Channel the direct current made from rotating the coils inside the generator to a power strip. This can be done by hard-wiring the generator's positive output cable to the power-strip directly. However, most modern generators have a standard electric outlet built in.
Plug electrical appliances into the power strip and use as normal.