Ideal temperatures of 65-75ºF (18-24ºC), and no lower than 50ºF (10ºC).
Bright light and for the variegated types some direct sunlight (couple of hours) can help them grow well. If the leaves are dark green in color it's best not to provide direct sun as it will harm them, but the variegated types may lose variegation if enough light is not provided. South, East or West facing windows are best suited, but again dependent on the leaf color.
Allow the top soil to dry out completely and then water thoroughly. You do not want to over water this plant and allow the soil to become waterlogged....so it might be best to lean towards less rather than too much when you first start growing Peperomias, as less harm can be caused compared to overwatering. During Winter water sparingly as the thick leaves will store water, so don't get too concerned about the soil being dry.
A peat based soil is best used that drains well. 2 parts peat and 1 part perlite or sand is a good mix. Other mixes will work well, but the main point is for the medium to drain well and be well aerated.
During Spring - while the plant is growing use a diluted liquid fertilizer once every 2 weeks, and once a month during summer. No feeding is required from Autumn to Spring.
You will not need to repot or pot up a size very often as this plant has a small root system. It's a good idea to change the soil or at least the top soil annually and if a young plant has out grown its current pot you may repot a size up during spring. Shallow pots are a good option for Peperomias.
* Standard care recommendations - you may need to adjust based on your home or office environment.