To build a bicycle generator you'll need the following parts. Bike, stand, DC generator, charge controller, batteries, and inverter.
The bike is placed in the stand with the rear tire on the generator. Then the generator is hooked up to the batteries through the charge controller. This prevent under and over charging your batteries. After that hook up your batteries to the inverter and you're done. The inverter will have a regular plug for electronics.
Use more batteries to store more energy or larger inverter to power more wattage at once. A 400 Watt inverter will be enough for most household electronics except an entire desktop computer setup. Go with 600 Watt if you want to be sure.