I've only got two of the moons detailed, and none of the three gas giants, but those will be forthcoming shortly. Aside from that, this is reasonably complete for the initial detailing. Later, I'll focus on each individual planet and draw up some basic maps with some of the major features.
The Inner Planets
The three Inner Worlds are where the majority of the system's inhabitants live. All the races originally came from Taladar, though with voidships having been around for close to fifty years, a sizable number have emigrated to Vela and Athelas. In terms of government, the only real nations are the three on Taladar. Each of the three has their own colonies on Vela and Athelas, in addition to the small, independent settlements.
Vela – Vela is the world closest to the sun. It is a hot, dusty world, with small seas of liquid water near the poles. The equatorial region is uninhabitable; all colonization efforts so far have been near the polar seas.
Taladar – The home world, Taladar is where all the races originate. A temperate planet, Taladar is the closest to Earth in terms of climate. With only two small continents, Taladar is a primarily-aquatic world. Naturally, those native to Taladar are typically well-versed in life near the water, with certain exceptions in the centers of the continents.
The two continents, Kalar and Volan, are small and separated by only a few hundred miles. Aside from them, the remaining dry land on Taladar is composed of islands. There are also frozen areas at the poles, but the cold temperatures have led most of the population to stay near the tropical equator and the continents.
Athelas – Athelas is the coldest of the three Inner Worlds. Though far more inhabitable than Vela, Athelas is a hard world. The winters last for endless months and the summers are comparable to a difficult autumn on Taladar. Most of the colonies are around the edges of the Great Forests, able to utilize the resources of the outer reaches of the woods, but not so far in as to be lost to whatever hellish creatures live in the hearts of the Forests.
There are four moons, each with its own colonies. Ranging from lush, tropical worlds to blasted hellscapes, the moons were only colonized within the last ten years due to their extreme distance from the Inner Worlds. Voidships take months to reach the closest; it's close to a year to get to the outer edge of the system.
Veras - Veras is a tropical world orbiting the first of the gas giants. Its atmosphere is oppressively hot and humid, leading to most of the world being covered in lush, thick jungles, with the exception of a few shallow seas. Veras is a small world, less than half the size of Taladar. The gravity is different enough that newcomers have to take plenty of time to get used to how to move without losing control. Walking, running, and jumping all have to be relearned to avoid hazardous falls and tumbles.
Seraal - The complete opposite of Veras, Seraal is a damned world. Devoid of almost all vegetation, Seraal is a planetary desert. There is a single, small sea, frozen over by the planet's eternal cold. The few settlers that have colonized the mon are only the hardiest of people, there primarily to delve into the depths of Seraal's caves in search of evidence that the Ancients had been there.