I think countries of teh world would be a fine place to start. There are already good tables in the major languages that can be translated easily.
The various elements would be another godo place to start, or the planets, all of which have similar tables and basic formats.
Some advantages to all of this is that these are articles that every language should have, they are neutral, and they are similarly formatted. They are also finite, so that there is a sense of accomplishment when they are done.
Danny