The Jehovah's Witnesses - Who Are They? brochure is an update of the older Jehovah's Witnesses in the Twentieth Century (likely because the title became outdated. The Twentieth Century brochure went through a few revisions over the years, too. It was actually a publicly-distributed revision of an earlier brochure called simply Jehovah's Witnesses that was mainly designed as an information piece for the press. All of these brochures gave a very general overview of who JW's are, what they believe, etc. and were basically intended as an introduction for someone who knew little or nothing about the Witnesses.
The brochure I think you're referring to, that was supposed to be covered with Bible studies, was called Jehovah's Witnesses - Unitedly Doing God's Will Worldwide, and went into a lot of detail about the organization, the worldwide work, various types of service, and so on. It was geared toward building loyalty toward the organization, and was definitely not the same as the Twentieth Century brochures in all their permutations. I'm pretty sure that the most recent edition of each brochure is on the WT CD-ROM.