For Macs, the universal StuffIt Expander tool will work. Depending on the computer system you are using the newsreader can be either an intuitive graphic interface or one that is based on commands. There is no limitation on the material in this group, making it a rather lively discussion area. Individuals post information on a topic, such as growing cannabis, and others will respond to the posting. Often with popular topics dozens of replies will be made.
Many postings are questions that people have about various drugs.
The quality of answers varies from simplistic or even wrong on the one hand, to quite complete and accurate discourses on the other hand. Many articles contain references that can be helpful, too. Additional, though somewhat less active newsgroups to check out are alt.psychoactives and alt.hemp. One thing about the net is that there is a comaraderie that tends to encourage people helping people. Inquiries are often made by people followed by an outrageously incorrect answer.