It depends. I think the biggest distinction is that it not be refrigerated. The warmer it's stored, the faster it'll carbonate, but the faster it'll age. Usually, around 70 degrees Fahrenheit is recommended as a middle ground.
Some people store their beer in the basement where the temps around low 60's, high 50's and fairly stable year-round. The beer will take longer to carbonate by a week or 2, depending on strength, but it'll age a lot slower and retain fresh flavors for a longer time.
Since I live in East Texas, my room temperature is usually upwards of 75 degrees. My beer carbonates within 2 weeks, but fades a lot faster than what I'd prefer. This is definitely not ideal, but I do the best with what I have.
In short, indoors at room temperature, as long as it isn't near 80 degrees.